Src homology 2 (SH2) domain found in the Cbl-b TKB domain; SH2 found in the Cbl-b TKB domain. The Cbl (for Casitas B-lineage lymphoma) family of E3 ubiquitin ligases contains three members Cbl, Cbl-b and Cbl-c. The founding member Cbl was discovered first as the oncogenic protein v-Cbl, a Gag-fusion transforming protein of Cas NS-1 retrovirus, which causes pre- and pro-B lymphomas in mice. The N-terminus of the Cbl proteins is composed of a tyrosine kinase-binding (TKB) domain, also called phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. In addition, Cbl and Cbl-b contain a leucine zipper motif and a proline-rich domain in the C-terminus. The TKB domain consists of a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain. Cbl-b plays a role in early hematopoietic development and is a negative regulator of T-cell receptor, B-cell receptor and high affinity immunoglobulin epsilon receptor signal transduction pathways. It also negatively regulates insulin-like growth factor 1 signaling during muscle atrophy caused by unloading and is involved in EGFR ubiquitination and internalization. Diseases associated with defects in Cbl-b include: multiple sclerosis, autoimmune diseases, including type 1 diabetes, and a craniofacial phenotype. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1242777557 242 NWNVLAVTHPGYVAFLTYDEVKARLQKYVTKPGSYVFRLSCTRLGQWAIGYVTAEGQILQTIPQNKSLCQALLDGQREGF 321
Cdd:cd09920     2 NWQVLAVTHPGYMAFLTYDEVKARLQKFRDKPGSYVFRLSCTRLGQWAIGYVTADGKILQTIPQNKSLCQALIDGSREGF 81

                          90
                  ....*....|....
gi 1242777557 322 FKYPDGRSINPDLS 335
Cdd:cd09920    82 YLYPDGRLDNPDLS 95

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Cbl and similar proteins; Cbl, also known as Casitas B-lineage lymphoma proto-oncogene, proto-oncogene c-Cbl, RING finger protein 55 (RNF55), or signal transduction protein Cbl, is a multi-domain protein that acts as a key negative regulator of various receptor and non-receptor tyrosine kinase signaling. It contains a tyrosine kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain), a proline-rich domain, a C3HC4-type RING-HC finger, and an ubiquitin-associated (UBA) domain. TKB is responsible for the interactions with many tyrosine kinases, such as the colony-stimulating factor-1 (CSF-1) receptor, Syk/ZAP-70, and Src-family of protein tyrosine kinases. The proline-rich domain can recruit proteins with a SH3 domain. Moreover, Cbl functions as an E3 ubiquitin ligase that can bind ubiquitin-conjugating enzymes (E2s) through the RING-HC finger.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1242777557 343 EDHIKVTQEQYELYCEMGSTFQLCKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEIKGTEQVVVDPF 419
Cdd:cd16708     1 QDHIKVTQEQYELYCEMGSTFQLCKICAENDKDVKIEPCGHLMCTSCLTSWQESEGQGCPFCRCEIKGTEPIVVDPF 77

Src homology 2 (SH2) domain found in the Cbl-b TKB domain; SH2 found in the Cbl-b TKB domain. The Cbl (for Casitas B-lineage lymphoma) family of E3 ubiquitin ligases contains three members Cbl, Cbl-b and Cbl-c. The founding member Cbl was discovered first as the oncogenic protein v-Cbl, a Gag-fusion transforming protein of Cas NS-1 retrovirus, which causes pre- and pro-B lymphomas in mice. The N-terminus of the Cbl proteins is composed of a tyrosine kinase-binding (TKB) domain, also called phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. In addition, Cbl and Cbl-b contain a leucine zipper motif and a proline-rich domain in the C-terminus. The TKB domain consists of a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain. Cbl-b plays a role in early hematopoietic development and is a negative regulator of T-cell receptor, B-cell receptor and high affinity immunoglobulin epsilon receptor signal transduction pathways. It also negatively regulates insulin-like growth factor 1 signaling during muscle atrophy caused by unloading and is involved in EGFR ubiquitination and internalization. Diseases associated with defects in Cbl-b include: multiple sclerosis, autoimmune diseases, including type 1 diabetes, and a craniofacial phenotype. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1242777557 242 NWNVLAVTHPGYVAFLTYDEVKARLQKYVTKPGSYVFRLSCTRLGQWAIGYVTAEGQILQTIPQNKSLCQALLDGQREGF 321
Cdd:cd09920     2 NWQVLAVTHPGYMAFLTYDEVKARLQKFRDKPGSYVFRLSCTRLGQWAIGYVTADGKILQTIPQNKSLCQALIDGSREGF 81

                          90
                  ....*....|....
gi 1242777557 322 FKYPDGRSINPDLS 335
Cdd:cd09920    82 YLYPDGRLDNPDLS 95

CBL proto-oncogene N-terminus, EF hand-like domain; Cbl is an adaptor protein that binds EGF receptors (or other tyrosine kinases) and SH3 domains, functioning as a negative regulator of many signaling pathways. The N-terminal domain is evolutionarily conserved, and is known to bind to phosphorylated tyrosine residues. The so called N-terminal domain is actually 3 structural domains, of which this is the central EF hand domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1242777557 164 FRITKSDAAEWWRKSFGDRTIVSWKVFRQTLHESHPISSPLEAMALKSTIDLTCNDYISVFDFDVFTRLFQPWVNLL*NW 243
Cdd:pfam02761   1 FRITKSEAAEFWKKSFGKRTIVPWKEFRTALQQVHGIESGLEAMALKSTIDLTCNDHISIFEFDVFTRLFQPWSTLLRNW 80

                  ....
gi 1242777557 244 NVLA 247
Cdd:pfam02761  81 NLLA 84

Prokaryotic RING finger family 4; RING finger family domain found sporadically in bacteria. The finger is fused to an N-terminal alpha-helical domain, ROT/Trove-like repeats and a C-terminal TerD domain. The architecture suggests a possible role in an RNA-processing complex.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCltqWQDSDGQGCPFCRTEIKGTeqvvvDPF 419
Cdd:pfam14447   1 CVLCGRNGTVHALIPCGHLVCRDC---FDGSDFSACPICRRRIDAD-----DPF 46

RING-finger-containing E3 ubiquitin ligase [Posttranslational modification, protein turnover, chaperones];

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQ-WQDSDGQGCPFCR 405
Cdd:COG5574   218 CFLCLEEPEVPSCTPCGHLFCLSCLLIsWTKKKYEFCPLCR 258

Src homology 2 (SH2) domain found in the Cbl-b TKB domain; SH2 found in the Cbl-b TKB domain. The Cbl (for Casitas B-lineage lymphoma) family of E3 ubiquitin ligases contains three members Cbl, Cbl-b and Cbl-c. The founding member Cbl was discovered first as the oncogenic protein v-Cbl, a Gag-fusion transforming protein of Cas NS-1 retrovirus, which causes pre- and pro-B lymphomas in mice. The N-terminus of the Cbl proteins is composed of a tyrosine kinase-binding (TKB) domain, also called phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. In addition, Cbl and Cbl-b contain a leucine zipper motif and a proline-rich domain in the C-terminus. The TKB domain consists of a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain. Cbl-b plays a role in early hematopoietic development and is a negative regulator of T-cell receptor, B-cell receptor and high affinity immunoglobulin epsilon receptor signal transduction pathways. It also negatively regulates insulin-like growth factor 1 signaling during muscle atrophy caused by unloading and is involved in EGFR ubiquitination and internalization. Diseases associated with defects in Cbl-b include: multiple sclerosis, autoimmune diseases, including type 1 diabetes, and a craniofacial phenotype. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1242777557 242 NWNVLAVTHPGYVAFLTYDEVKARLQKYVTKPGSYVFRLSCTRLGQWAIGYVTAEGQILQTIPQNKSLCQALLDGQREGF 321
Cdd:cd09920     2 NWQVLAVTHPGYMAFLTYDEVKARLQKFRDKPGSYVFRLSCTRLGQWAIGYVTADGKILQTIPQNKSLCQALIDGSREGF 81

                          90
                  ....*....|....
gi 1242777557 322 FKYPDGRSINPDLS 335
Cdd:cd09920    82 YLYPDGRLDNPDLS 95

CBL proto-oncogene N-terminus, EF hand-like domain; Cbl is an adaptor protein that binds EGF receptors (or other tyrosine kinases) and SH3 domains, functioning as a negative regulator of many signaling pathways. The N-terminal domain is evolutionarily conserved, and is known to bind to phosphorylated tyrosine residues. The so called N-terminal domain is actually 3 structural domains, of which this is the central EF hand domain.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1242777557 164 FRITKSDAAEWWRKSFGDRTIVSWKVFRQTLHESHPISSPLEAMALKSTIDLTCNDYISVFDFDVFTRLFQPWVNLL*NW 243
Cdd:pfam02761   1 FRITKSEAAEFWKKSFGKRTIVPWKEFRTALQQVHGIESGLEAMALKSTIDLTCNDHISIFEFDVFTRLFQPWSTLLRNW 80

                  ....
gi 1242777557 244 NVLA 247
Cdd:pfam02761  81 NLLA 84

RING finger, HC subclass, found in E3 ubiquitin-protein ligase Cbl-b and similar proteins; Cbl-b, also known as Casitas B-lineage lymphoma proto-oncogene b, RING finger protein 56 (RNF56), SH3-binding protein Cbl-b, or signal transduction protein Cbl-b, has been identified as a regulator of antigen-specific, T cell-intrinsic, peripheral immune tolerance, a state also known as clonal anergy. It may inhibit activation of the p85 subunit of phosphoinositide 3-kinase (PI3K), protein kinase C-theta (PKC-theta), and phospholipase C-gamma1 (PLC-gamma1) and negatively regulates T-cell receptor-induced transcription factor nuclear factor kappaB (NF-kappaB) activation. In addition, Cbl-b may target multiple signaling molecules involved in transforming growth factor (TGF)-beta-mediated transactivation pathways. Cbl-b contains a tyrosine-kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, is composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain), a proline rich domain, a nuclear localization signal, a C3HC4-type RING-HC finger and an ubiquitin-associated (UBA) domain.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1242777557 344 DHIKVTQEQYELYCEMGSTFQLCKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEIKGTEQVVVDPF 419
Cdd:cd16709     1 DHIKVTQEQYELYCEMGSTFQLCKICAENDKDVKIEPCGHLMCTSCLTAWQESDGQGCPFCRCEIKGTEPIIVDPF 76

RING finger, HC subclass, found in Casitas B-lineage lymphoma (Cbl) proteins; The Cbl adaptor protein family contains a small class of RING-type E3 ubiquitin ligases with oncogenic activity, which is represented by three mammalian members, c-Cbl, Cbl-b and Cbl-c, as well as two invertebrate Cbl-family proteins, D-Cbl in Drosophila and Sli-1 in C. elegans. Cbl proteins function as potent negative regulators of various signaling cascades in a wide range of cell types. They play roles in ubiquitinating activated tyrosine kinases and targeting them for degradation. D-Cbl associates with the Drosophila epidermal growth factor receptor (EGFR) and overexpression of D-Cbl in the eye of Drosophila embryos inhibits EGFR-dependent photoreceptor cell development. Sli-1 is a negative regulator of the Let-23 receptor tyrosine kinase, an EGFR homolog, in vulva development. Cbl proteins in this subfamily consist of a highly conserved N-terminal half that includes a tyrosine-kinase-binding domain (TKB, also known as the phosphotyrosine binding PTB domain, composed of a four helix-bundle, a Ca2+ binding EF-hand and a highly variant SH2 domain) and a C3HC4-type RING-HC finger, both of which are required for Cbl-mediated downregulation of RTKs, and a divergent C-terminal region.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1242777557 363 FQLCKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQGCPFCR 405
Cdd:cd16502     1 FQLCKICAENDKDVRIEPCGHLLCTPCLTSWQDSDGQTCPFCR 43

Zinc finger, C3HC4 type (RING finger);

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1242777557 364 QLCKICAENDKDIRIEPCGHL-LCTPCLTQWQdSDGQGCPFCRTEIKGT 411
Cdd:pfam13920   3 LLCVICLDRPRNVVLLPCGHLcLCEECAERLL-RKKKKCPICRQPIESV 50

Zinc finger, C3HC4 type (RING finger); The C3HC4 type zinc-finger (RING finger) is a cysteine-rich domain of 40 to 60 residues that coordinates two zinc ions, and has the consensus sequence: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C where X is any amino acid. Many proteins containing a RING finger play a key role in the ubiquitination pathway.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1242777557 366 CKICAENDKDI-RIEPCGHLLCTPCLTQWQDSDGQGCPFC 404
Cdd:pfam00097   1 CPICLEEPKDPvTLLPCGHLFCSKCIRSWLESGNVTCPLC 40

RING finger (Really Interesting New Gene) domain and U-box domain superfamily; The RING finger is a specialized type of Zn-finger of 40 to 60 residues that binds two atoms of zinc. It is defined by the "cross-brace" motif that chelates zinc atoms by eight amino acid residues, typically Cys or His, arranged in a characteristic spacing. Canonical RING motifs have been categorized into two major subclasses, RING-HC (C3HC4-type) and RING-H2 (C3H2C3-type), according to their Cys/His content. There are also many variants of RING fingers: some have different Cys/His patterns while some lack a single Cys or His residue at typical Zn ligand positions (the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can indeed chelate Zn in a RING finger as well). C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type RING fingers are closely related to RING-HC fingers. In contrast, C4HC3- (RING-CH alias RINGv), C3H3C2-, C3H2C2D-, C3DHC3-, and C4HC2H-type RING fingers are more closely related to RING-H2 fingers. However, not all RING finger-containing proteins display regular RING finger features, and the RING finger family has turned out to be multifarious. The degenerate RING fingers of the Siz/PIAS RING (SP-RING) family proteins and sporulation protein RMD5, are characterized by lacking the second, fifth, and sixth Zn2+ ion-coordinating residues. They bind only one Zn2+ ion. On the other hand, the RING fingers of the human APC11 and RBX1 proteins can bind a third Zn atom since they harbor four additional Zn ligands. U-box is a modified form of the RING finger domain that lacks metal chelating Cys and His residues. It resembles the cross-brace RING structure consisting of three beta-sheets and a single alpha-helix, which would be stabilized by salt bridges instead of chelated metal ions. U-box proteins are widely distributed among eukaryotic organisms and show a higher prevalence in plants than in other organisms. RING finger/U-box-containing proteins are a group of diverse proteins with a variety of cellular functions, including oncogenesis, development, viral replication, signal transduction, the cell cycle and apoptosis. Many of them are ubiquitin-protein ligases (E3s) that serve as scaffolds for binding to ubiquitin-conjugating enzymes (E2s, also referred to as ubiquitin carrier proteins or UBCs) in close proximity to substrate proteins, which enable efficient transfer of ubiquitin from E2 to the substrates.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1242777557 366 CKICAENDKDIR---IEPCGHLLCTPCLTQWQDSDGQGCPFC 404
Cdd:cd00162     1 CPICREEMNDRRpvvLLSCGHTFSRSAIARWLEGSKQKCPFC 42

RING finger, HC subclass, found in RING finger protein 5 (RNF5) and similar proteins; RNF5, also known as protein G16 or Ram1, is an E3 ubiquitin-protein ligase anchored to the outer membrane of the endoplasmic reticulum (ER). It acts at early stages of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) biosynthesis and functions as a target for therapeutic modalities to antagonize mutant CFTR proteins in CF patients carrying the F508del allele. It also regulates the turnover of specific G protein-coupled receptors by ubiquitinating JNK-associated membrane protein (JAMP) and preventing proteasome recruitment. RNF5 limits basal levels of autophagy and influences susceptibility to bacterial infection through the regulation of ATG4B stability. It is also involved in the degradation of Pendrin, a transmembrane chloride/anion exchanger highly expressed in thyroid, kidney, and inner ear. RNF5 plays an important role in cell adhesion and migration. It can modulate cell migration by ubiquitinating paxillin. Furthermore, RNF5 interacts with virus-induced signaling adaptor (VISA) at mitochondria in a viral infection-dependent manner, and further targets VISA at K362 and K461 for K48-linked ubiquitination and degradation after viral infection. It also negatively regulates virus-triggered signaling by targeting MITA, also known as STING, for ubiquitination and degradation at the mitochondria. In addition, RNF5 determines breast cancer response to ER stress-inducing chemotherapies through the regulation of the L-glutamine carrier proteins SLC1A5 and SLC38A2 (SLC1A5/38A2). It also has been implicated in muscle organization and in recognition and processing of misfolded proteins. RNF5 contains a C3HC4-type RING-HC finger.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQWQDS--DGQGCPFCRTEIkGTEQVV 415
Cdd:cd16743     3 CNICLETARDAVVSLCGHLFCWPCLHQWLETrpERQECPVCKAGI-SRDKVI 53

RING finger, HC subclass, found in RING finger protein 138 (RNF138) and similar proteins; RNF138, also known as Nemo-like kinase-associated RING finger protein (NARF) or NLK-associated RING finger protein, is an E3 ubiquitin-protein ligase that plays an important role in glioma cell proliferation, apoptosis, and cell cycle. It specifically cooperates with the E2 conjugating enzyme E2-25K (Hip-2/UbcH1), regulates the ubiquitylation and degradation of T cell factor/lymphoid enhancer factor (TCF/LEF), and further suppresses Wnt-beta-catenin signaling. RNF138, together with three closely related proteins: RNF114, RNF125 and RNF166, forms a novel family of ubiquitin ligases with a C3HC4-type RING-HC finger, a C2HC-, and two C2H2-type zinc fingers, as well as a ubiquitin interacting motif (UIM).

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1242777557 365 LCKICAENDKD-IRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEIKGTE 412
Cdd:cd16544     4 TCPVCQEVLKDpVELPPCRHIFCKACILLALRSSGARCPLCRGPVGKTE 52

RING finger, HC subclass, found in helicase-like transcription factor (HLTF) and similar proteins; HLTF, also known as DNA-binding protein/plasminogen activator inhibitor 1 regulator, HIP116, RING finger protein 80, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 3, or sucrose nonfermenting protein 2-like 3, is a yeast RAD5 homolog found in mammals. It has both E3 ubiquitin ligase and DNA helicase activities, and plays a pivotal role in the template-switching pathway of DNA damage tolerance. It is involved in Lys-63-linked poly-ubiquitination of proliferating cell nuclear antigen (PCNA) at Lys-164 and in the regulation of DNA damage tolerance. It shows double-stranded DNA translocase activity with 3'-5' polarity, thereby facilitating regression of the replication fork. HLTF contains an N-terminal HIRAN (HIP116 and RAD5 N-terminal) domain, a SWI/SNF helicase domain that is divided into N- and C-terminal parts by an insertion of a C3HC4-type RING-HC finger involved in the poly-ubiquitination of PCNA.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEIK 409
Cdd:cd16509     6 CAICLDSLTNPVITPCAHVFCRRCICEVIQREKAKCPMCRAPLS 49

RING finger, HC subclass, found in inhibitor of apoptosis proteins (IAPs); IAPs are frequently overexpressed in cancer and associated with tumor cell survival, chemoresistance, disease progression, and poor prognosis. They function primarily as negative regulators of cell death. They regulate caspases and apoptosis through the inhibition of specific members of the caspase family of cysteine proteases. In addition, IAPs has been implicated in a multitude of other cellular processes, including inflammatory signalling and immunity, mitogenic kinase signalling, proliferation and mitosis, as well as cell invasion and metastasis. IAPs in this family includes cellular inhibitor of apoptosis protein c-IAP1 (BIRC2) and c-IAP2 (BIRC3), XIAP (BIRC4), BIRC7, and BIRC8, all of which contain three N-terminal baculoviral IAP repeat (BIR) domains that enable interactions with proteins, a ubiquitin-association (UBA) domain that is responsible for the binding of polyubiquitin (polyUb), and a C3HC4-type RING-HC finger at the carboxyl terminus that is required for ubiquitin ligase activity. The UBA domain is only absent in mammalian homologs of BIRC7. Moreover, c-IAPs contains an additional caspase activation and recruitment domain (CARD) between the UBA and C3HC4-type RING-HC domains. The CARD domain may serve as a protein interaction surface.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1242777557 364 QLCKICAENDKDIRIEPCGHLL----CTPCLTQwqdsdgqgCPFCRT 406
Cdd:cd16510     2 KLCKICMDREVNIVFLPCGHLVtcaqCAASLRK--------CPICRT 40

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1A (NEURL1A) and similar proteins; NEURL1A, also known as NEURL1, NEU, neuralized 1, or RING finger protein 67 (RNF67), is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that directly interacts with and monoubiquitinates cytoplasmic polyadenylation element-binding protein 3 (CPEB3), an RNA binding protein and a translational regulator of local protein synthesis, which facilitates hippocampal plasticity and hippocampal-dependent memory storage. It also acts as a potential tumor suppressor that causes apoptosis and downregulates Notch target genes in the medulloblastoma. NEURL1A contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1242777557 360 GSTFQLCKICAENDKDIRIEPCGHL-LCTPCLTQWQDSDGQGCPFCRTEIK 409
Cdd:cd16785     1 GSWSDECTICYENAVDTVIYTCGHMcLCYACGLRLKKMLNACCPICRRAIK 51

RING finger, HC subclass, found in peroxin-10 (PEX10) and similar proteins; PEX10, also known as peroxisome biogenesis factor 10, peroxisomal biogenesis factor 10, peroxisome assembly protein 10, or RING finger protein 69 (RNF69), is an integral peroxisomal membrane protein with two transmembrane regions and a C3HC4-type RING-HC finger within its cytoplasmically exposed C-terminus. It plays an essential role in peroxisome assembly, import of target substrates, and recycling or degradation of protein complexes and amino acids. It is an essential component of the spinal locomotor circuit, and thus its mutations may be involved in peroxisomal biogenesis disorders (PBD). Mutations in human PEX10 also result in autosomal recessive ataxia. Moreover, PEX10 functions as an E3-ubiquitin ligase with an E2, UBCH5C. It mono- or poly-ubiquitinates PEX5, a key player in peroxisomal matrix protein import, in a UBC4-dependent manner, to control PEX5 receptor recycling or degradation. It also links the E2 ubiquitin conjugating enzyme PEX4 to the protein import machinery of the peroxisome.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQgCPFCRTEIK 409
Cdd:cd16527     3 CSLCLEERRHPTATPCGHLFCWSCITEWCNEKPE-CPLCREPFQ 45

RING finger, HC subclass, found in RING finger protein 141 (RNF141) and similar proteins; RNF141, also known as zinc finger protein 230 (ZNF230), is a RING finger protein present primarily in the nuclei of spermatogonia, the acrosome, and the tail of spermatozoa. It may have a broad function during early development of vertebrates. It plays an important role in spermatogenesis, including spermatogenic cell proliferation and sperm maturation, as well as motility and fertilization. It also exhibits DNA binding activity. RNF141/ZNF230 gene mutations may be associated with azoospermia. RNF141 contains a C3HC4-type RING finger domain that may function as an activator module in transcription.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 1242777557 366 CKICAENDKDIrIEPCGHLLCTPCLTQWQDSDGQgCPFCR 405
Cdd:cd16545     3 CCICMDRKADL-ILPCAHSYCQKCIDKWSDRHRT-CPICR 40

RING finger, HC subclass, found in RING finger and transmembrane domain-containing protein RNFT1, RNFT2, and similar proteins; Both RNFT1 and RNFT2 are multi-pass membrane proteins containing a C3HC4-type RING-HC finger. Their biological roles remain unclear.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1242777557 365 LCKICAENDKDIRIEPCGHLLCTPCLTQWQDSDgQGCPFCR 405
Cdd:cd16532     2 ICPICQDEFKDPVVLRCKHIFCEDCVSEWFERE-RTCPLCR 41

RING finger, HC subclass, found in Saccharomyces cerevisiae POB3/SPT16 histone-associated protein 1 (ScPSH1) and similar proteins; ScPSH1 is a Cse4-specific E3 ubiquitin ligase that interacts with the kinetochore protein Pat1 and targets the degradation of budding yeast centromeric histone H3 variant, CENP-ACse4, which is essential for faithful chromosome segregation. ScPSH1 contains a C3HC4-type RING-HC finger and a DNA directed RNA polymerase domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1242777557 364 QLCKICAENDKDIRIEPCGHLLCTPCLTQWQDS-DGQGCPFCRTEIK 409
Cdd:cd16568     5 QECIICHEYLYEPMVTTCGHTYCYTCLNTWFKSnRSLSCPDCRTKIT 51

RING finger, H2 subclass, found in RING finger protein 165 (RNF165) and similar proteins; RNF165, also known as Arkadia-like 2, Arkadia2, or Ark2C, is an E3 ubiquitin ligase with homology to the C-terminal half of RNF111. It is expressed specifically in the nervous system, and can serve to amplify neuronal responses to specific signals. It acts as a positive regulator of bone morphogenetic protein (BMP)-Smad signaling that is involved in motor neuron (MN) axon elongation. RNF165 contains two serine rich domains, a nuclear localization signal, an NRG-TIER domain, and a C-terminal C3H2C3-type RING-H2 finger that is responsible for the enhancement of BMP-Smad1/5/8 signaling in the spinal cord.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1242777557 358 EMGSTFQLCKICA---ENDKDIRIEPCGHLLCTPCLTQWQdSDGQGCPFCRTEIK 409
Cdd:cd16682     2 EESDTDEKCTICLsmlEDGEDVRRLPCMHLFHQLCVDQWL-AMSKKCPICRVDIE 55

RING finger, HC subclass, found in tripartite motif-containing protein 40 (TRIM40) and similar proteins; TRIM40, also known as probable E3 NEDD8-protein ligase or RING finger protein 35 (RNF35), is highly expressed in the gastrointestinal tract including the stomach, small intestine, and large intestine. It enhances neddylation of inhibitor of nuclear factor kappaB kinase subunit gamma (IKKgamma), inhibits the activity of nuclear factor-kappaB (NF-kappaB)-mediated transcription, and thus prevents inflammation-associated carcinogenesis in the gastrointestinal tract. TRIM40 belongs to the C-V subclass of the TRIM (tripartite motif) family of proteins that are defined by an N-terminal RBCC (RING, Bbox, and coiled coil) domain, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as an uncharacterized region positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1242777557 365 LCKICAENDKDIRIEPCGHLLCTPCLTQWQD----SDGQGCPFCRT 406
Cdd:cd16583     7 VCPICQEPLKEAVSTDCGHLFCRMCLTQHAKkasaSGVFSCPVCRK 52

RING finger, H2 subclass, found in autocrine motility factor receptor (AMFR) and similar proteins; AMFR, also known as AMF receptor, or RING finger protein 45, or ER-protein gp78, is an internalizing cell surface glycoprotein localized in both plasma membrane caveolae and the endoplasmic reticulum (ER). It is involved in the regulation of cellular adhesion, proliferation, motility and apoptosis, as well as in the process of learning and memory. AMFR also functions as a RING finger-dependent ubiquitin protein ligase (E3) implicated in the degradation from the ER. AMFR contains an N-terminal RING-H2 finger and a C-terminal ubiquitin-associated (UBA)-like CUE domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQWQDSDgQGCPFCRT 406
Cdd:cd16455     3 CAICWESMQSARKLPCGHLFHNSCLRSWLEQD-TSCPTCRM 42

RING finger, HC subclass, found in Equid alphaherpesvirus 1 (Equine herpesvirus 1/EHV-1) regulatory protein and similar proteins; EHV-1 regulatory protein belongs to the Vmw110 (IPC0) protein family. It contains a typical C3HC4-type RING-HC finger and binds zinc stably.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1242777557 366 CKICAENDKDIRIE-PCGHLLCTPCLTQWQDSDGQgCPFCRTEIKGT 411
Cdd:cd23130     3 CPICLDDPEDEAITlPCLHQFCYTCILRWLQTSPT-CPLCKTPVTSI 48

RING finger, H2 subclass, found in RING finger protein 111 (RNF111) and similar proteins; RNF111, also known as Arkadia, is a nuclear E3 ubiquitin-protein ligase that targets intracellular effectors and modulators of transforming growth factor beta (TGF-beta)/Nodal-related signaling for polyubiquitination and proteasome-dependent degradation. It acts as an amplifier of Nodal signals, and enhances the dorsalizing activity of limiting amounts of Xnr1, a Nodal homolog, and requires Nodal signaling for its function. The loss of RNF111 results in early embryonic lethality, with defects attributed to compromised Nodal signaling. RNF111 also regulates tumor metastasis by modulation of the TGF-beta pathway. Its ubiquitination can be modulated by the four and a half LIM-only protein 2 (FHL2) that activates TGF-beta signal transduction. Furthermore, RNF111 interacts with the clathrin-adaptor 2 (AP2) complex and regulates endocytosis of certain cell surface receptors, leading to modulation of epidermal growth factor (EGF) and possibly other signaling pathways. In addition, RNF111 has been identified as a small ubiquitin-like modifier (SUMO)-binding protein with clustered SUMO-interacting motifs (SIMs) that together form a SUMO-binding domain (SBD). It thus functions as a SUMO-targeted ubiquitin ligase (STUbL) that directly links nonproteolytic ubiquitylation and SUMOylation in the DNA damage response, as well as triggers degradation of signal-induced polysumoylated proteins, such as the promyelocytic leukemia protein (PML). The N-terminal half of RNF111 harbors three SIMs. Its C-terminal half show high sequence similarity with RING finger protein 165 (RNF165), where it contains two serine rich domains, two nuclear localization signals, an NRG-TIER domain, and a C-terminal C3H2C3-type RING-H2 finger that is required for polyubiqutination and proteasome-dependent degradation of phosphorylated forms of Smad2/3 and three major negative regulators of TGF-beta signaling, Smad7, SnoN and c-Ski.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1242777557 362 TFQLCKICA---ENDKDIRIEPCGHLLCTPCLTQWQDSDgQGCPFCRTEIK 409
Cdd:cd16681     9 TEEKCTICLsilEEGEDVRRLPCMHLFHQVCVDQWLITN-KKCPICRVDIE 58

RING finger, HC subclass, found in checkpoint with forkhead and RING finger domains protein (CHFR); CHFR, also known as RING finger protein 196 (RNF196), is a checkpoint protein that delays entry into mitosis in response to stress. It functions as an E3 ubiquitin ligase that ubiquitinates and degrades its target proteins, such as Aurora-A, Plk1, Kif22, and PARP-1, which are critical for proper mitotic transitions. It also plays an important role in cell cycle progression and tumor suppression, and is negatively regulated by SUMOylation-mediated proteasomal ubiquitylation. Moreover, CHFR is involved in the early stage of the DNA damage response, which mediates the crosstalk between ubiquitination and poly-ADP-ribosylation. CHFR contains a fork head associated (FHA) domain and a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1242777557 366 CKICAENDKD-IRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEIKG 410
Cdd:cd16503     5 CSICQDLLHDcVSLQPCMHNFCAACYSDWMERSNTECPTCRATVQR 50

RING finger, HC subclass, found in RNA-binding protein MEX3C; MEX3C, also known as RING finger and KH domain-containing protein 2 (RKHD2), or RING finger protein 194 (RNF194), is an RNA-binding phosphoprotein that acts as a suppressor of chromosomal instability. It functions as an ubiquitin E3 ligase responsible for the post-transcriptional, HLA-A allotype-specific regulation of MHC class I molecules (MHC-I). It also modifies retinoic acid inducible gene-1 (RIG-I) in stress granules and plays a critical role in eliciting antiviral immune responses. Moreover, MEX3C plays an essential role in normal postnatal growth via enhancing the local expression of insulin-like growth factor 1 (IGF1) in bone. It may also be involved in metabolic regulation of energy balance. MEX3C contains two K homology (KH) domains that provide RNA-binding capacity, and a C-terminal C3HC4-type RING-HC finger. Like other MEX-3 family proteins, MEX3C shuttles between the nucleus and the cytoplasm via the CRM1-dependent export pathway.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1242777557 366 CKICAENDKDIRIEPCGH-LLCTPCLTQWQDSDGQGCPFCRTEIKGTEQV 414
Cdd:cd16722     4 CVICFENEVIAALVPCGHnLFCMECANKICEKETPSCPVCQTAVTQAIQI 53

RING-finger-containing ubiquitin ligase [Posttranslational modification, protein turnover, chaperones];

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1242777557 366 CKICAEN---DKDIRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEI 408
Cdd:COG5540   326 CAICMSNfikNDRLRVLPCDHRFHVGCVDKWLLGYSNKCPVCRTAI 371

RING finger, H2 subclass, found in RING finger proteins RNF139, RNF145, and similar proteins; RNF139, also known as translocation in renal carcinoma on chromosome 8 protein (TRC8), is an endoplasmic reticulum (ER)-resident multi-transmembrane protein that functions as a potent growth suppressor in mammalian cells, inducing G2/M arrest, decreased DNA synthesis and increased apoptosis. It is a tumor suppressor that has been implicated in a novel regulatory relationship linking the cholesterol/lipid biosynthetic pathway with cellular growth control. A mutation in RNF139 has been identified in families with hereditary renal (RCC) and thyroid cancers. RNF145 is an uncharacterized RING finger protein encoded by the RNF145 gene, which is expressed in T lymphocytes, and its expression is altered in acute myelomonocytic and acute promyelocytic leukemias. Although its biological function remains unclear, RNF145 shows high sequence similarity with RNF139. Both RNF139 and RNF145 contain a C3H2C3-type RING-H2 finger with possible E3-ubiquitin ligase activity.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1242777557 365 LCKICAENDKDIRIEPCGHLLCTPCLTQW---QDSdgqgCPFC 404
Cdd:cd16476     2 VCAICYQEMKEARITPCNHFFHGLCLRKWlyvQDT----CPLC 40

RING finger, HC subclass, found in mind bomb MIB1, MIB2, RGLG1, RGLG2, and similar proteins; MIBs are large, multi-domain E3 ubiquitin-protein ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. They are also responsible for TBK1 K63-linked ubiquitination and activation, promoting interferon production and controlling antiviral immunity. Moreover, MIBs selectively control responses to cytosolic RNA and regulate type I interferon transcription. Both MIB1 and MIB2 have similar domain architectures, which consist of two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region, where MIB1 and MIB2 contain three and two C3HC4-type RING-HC fingers, respectively. This model corresponds to the third RING-HC finger of MIB1, as well as the second RING-HC finger of MIB2. In addition to MIB1 and MIB2, the RING-HC fingers of RING domain ligase RGLG1, RGLG2 and similar proteins from plant are also included in this model. RGLG1 is a ubiquitously expressed E3 ubiquitin-protein ligase that interacts with UBC13 and, together with UBC13, catalyzes the formation of K63-linked polyubiquitin chains, which is involved in DNA damage repair. RGLG1 mediates the formation of canonical, K48-linked polyubiquitin chains that target proteins for degradation. It also regulates apical dominance by acting on the auxin transport proteins abundance. RGLG1 has overlapping functions with its closest sequelog, RGLG2. They both function as RING E3 ligases that interact with ethylene response factor 53 (ERF53) in the nucleus and negatively regulate the plant drought stress response. All RGLG proteins contain a Von Willebrand factor type A (vWA) domain and a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1242777557 364 QLCKICAENDKDIrIEPCGHLLCTPCLTQWQDsdgqgCPFCRTEI 408
Cdd:cd16520     1 ILCPICMERKKNV-VFLCGHGTCQKCAEKLKK-----CPICRKPI 39

RING finger, HC subclass, found in RING finger and transmembrane domain-containing protein 2(RNFT2); RNFT2, also known as transmembrane protein 118 (TMEM118), is a multi-pass membrane protein containing a C3HC4-type RING-HC finger. Its biological role remains unclear.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1242777557 365 LCKICAENDKDIRIEPCGHLLCTPCLTQWQDSDgQGCPFCRT 406
Cdd:cd16742    15 ICAICQAEFREPLILICQHVFCEECLCLWFDRE-RTCPLCRS 55

RING finger, HC subclass, found in RING finger protein 219 (RNF219) and similar proteins; RNF219 may function as a modulator of late-onset Alzheimer's disease (LOAD) associated amyloid beta A4 precursor protein (APP) endocytosis and metabolism. It genetically interacts with apolipoprotein E epsilon4 allele (APOE4). Thus, a genetic variant of RNF219 was found to affect amyloid deposition in human brain and LOAD age-of-onset. Moreover, common genetic variants at the RNF219 locus had been associated with alternations in lipid metabolism, cognitive performance and central nervous system ventricle volume. RNF219 contains a C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQgCPFCRTEI 408
Cdd:cd16562     4 CHICLGKVRQPVICSNNHVFCSSCMDVWLKNNNQ-CPACRVPI 45

RING finger, HC subclass, found in tripartite motif-containing protein 39 (TRIM39) and similar proteins; TRIM39, also known as RING finger protein 23 (RNF23) or testis-abundant finger protein, is an E3 ubiquitin-protein ligase that plays a role in controlling DNA damage-induced apoptosis through inhibition of the anaphase promoting complex (APC/C), a multiprotein ubiquitin ligase that controls multiple cell cycle regulators, including cyclins, geminin, and others. TRIM39 also functions as a regulator of several key processes in the proliferative cycle. It directly regulates p53 stability. It modulates cell cycle progression and DNA damage responses via stabilizing p21. Moreover, TRIM39 negatively regulates the nuclear factor kappaB (NFkappaB)-mediated signaling pathway through stabilization of Cactin, an inhibitor of NFkappaB- and Toll-like receptor (TLR)-mediated transcription, which is induced by inflammatory stimulants such as tumor necrosis factor alpha. Furthermore, TRIM39 is a MOAP-1-binding protein that can promote apoptosis signaling through stabilization of MOAP-1 via the inhibition of its poly-ubiquitination process. TRIM39 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1242777557 365 LCKICAENDKDIRIEPCGHLLCTPCLTQ-WQDSDGQ-GCPFC 404
Cdd:cd16601     3 SCSLCKEYLKDPVIIECGHNFCRACITRfWEELDGDfPCPQC 44

RING finger, HC subclass, found in tripartite motif-containing protein 32 (TRIM32) and similar proteins; TRIM32, also known as 72 kDa Tat-interacting protein, zinc finger protein HT2A, or BBS11, is an E3 ubiquitin-protein ligase that promotes degradation of several targets, including actin, PIASgamma, Abl interactor 2, dysbindin, X-linked inhibitor of apoptosis (XIAP), p73 transcription factor, thin filaments and Z-bands during fasting. It plays important roles in neuronal differentiation of neural progenitor cells, as well as in controlling cell fate in skeletal muscle progenitor cells. It reduces PI3K-Akt-FoxO signaling in muscle atrophy by promoting plakoglobin-PI3K dissociation. It also functions as a pluripotency-reprogramming roadblock that facilitates cellular transition towards differentiation by modulating the levels of Oct4 and cMyc. Moreover, TRIM32 is an intrinsic influenza A virus (IAV) restriction factor which senses and targets the polymerase basic protein 1 (PB1) for ubiquitination and protein degradation. It also plays a significant role in mediating the biological activity of the HIV-1 Tat protein in vivo, binds specifically to the activation domain of HIV-1 Tat, and can also interact with the HIV-2 and EIAV Tat proteins in vivo. Furthermore, TRIM32 regulates myoblast proliferation by controlling turnover of NDRG2 (N-myc downstream-regulated gene). It negatively regulates tumor suppressor p53 to promote tumorigenesis. It also facilitates degradation of MYCN on spindle poles and induces asymmetric cell division in human neuroblastoma cells. In addition, TRIM32 plays important roles in regulation of hyperactivities and positively regulates the development of anxiety and depression disorders induced by chronic stress. It also plays a role in regeneration by affecting satellite cell cycle progression via modulation of the SUMO ligase PIASy (PIAS4). Defects in TRIM32 leads to limb-girdle muscular dystrophy type 2H (LGMD2H), sarcotubular myopathies (STM) and Bardet-Biedl syndrome. TRIM32 belongs to the C-VII subclass of the TRIM (tripartite motif)-NHL family that is defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil domain, as well as a NHL (named after proteins NCL-1, HT2A and Lin-41 that contain repeats folded into a six-bladed beta propeller) repeat domain positioned C-terminal to the RBCC domain. The NHL domain mediates the interaction with Argonaute proteins and consequently allows TRIM32 to modulate the activity of certain miRNAs.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1242777557 366 CKICAE--NDKDI--RIEPCGHLLCTPCLTQWQDSDGQG---CPFCR 405
Cdd:cd16587     3 CPICLEsfDEGQLrpKLLHCGHTICEQCLEKLLASLSINgvrCPFCR 49

RING finger, HC subclass, found in RING finger protein 222 (RNF222) and similar proteins; RNF222 is an uncharacterized C3HC4-type RING-HC finger-containing protein. It may function as an E3 ubiquitin-protein ligase.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1242777557 366 CKICAENDKDI-RIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEI 408
Cdd:cd16564     3 CPVCYEDFDDApRILSCGHSFCEDCLVKQLVSMTISCPICRRVT 46

RING finger, HC subclass, found in tripartite motif-containing protein TRIM25 and similar proteins; TRIM25, also known as estrogen-responsive finger protein (EFP), RING finger protein 147 (RNF147), or RING-type E3 ubiquitin transferase, is an E3 ubiquitin/ISG15 ligase that is induced by estrogen and is therefore particularly abundant in placenta and uterus. TRIM25 regulates various cellular processes through E3 ubiquitin ligase activity, transferring ubiquitin and ISG15 to target proteins. It mediates K63-linked polyubiquitination of retinoic acid inducible gene I (RIG-I) that is crucial for downstream antiviral interferon signaling. It is also required for melanoma differentiation-associated gene 5 (MDA5) and mitochondrial antiviral signaling (MAVS, also known as IPS-1, VISA, Cardiff) mediated activation of nuclear factor-kappaB (NF-kappaB) and interferon production. Upon UV irradiation, TRIM25 interacts with mono-ubiquitinated PCNA and promotes its ISG15 modification (ISGylation), suggesting a crucial role in termination of error-prone translesion DNA synthesis. TRIM25 also functions as a novel regulator of p53 and Mdm2. It enhances p53 and Mdm2 abundance by inhibiting their ubiquitination and degradation in 26S proteasomes. Meanwhile, it inhibits p53's transcriptional activity and dampens the response to DNA damage, and is essential for medaka development and this dependence is rescued by silencing of p53. Moreover, TRIM25 is involved in the host cellular innate immune response against retroviral infection. It interferes with the late stage of feline leukemia virus (FeLV) replication. Furthermore, TRIM25 acts as an oncogene in gastric cancer. Its blockade by RNA interference inhibits migration and invasion of gastric cancer cells through transforming growth factor-beta (TGF-beta) signaling, suggesting it presents a novel target for the detection and treatment of gastric cancer. In addition, TRIM25 acts as an RNA-specific activator for Lin28a/TuT4-mediated uridylation. TRIM25 belongs to the C-IV subclass of TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQ---WQDSDGQGCPFCRTE 407
Cdd:cd16597     8 CSICLELFKDPVTLPCGHNFCGVCIEKtwdSQHGSEYSCPQCRAT 52

RING finger, HC subclass, found in tripartite motif-containing protein 56 (TRIM56) and similar proteins; TRIM56, also known as RING finger protein 109 (RNF109), is a virus-inducible E3 ubiquitin ligase that restricts pestivirus infection. It positively regulates the Toll-like receptor 3 (TLR3) antiviral signaling pathway, and possesses antiviral activity against bovine viral diarrhea virus (BVDV), a ruminant pestivirus classified within the family Flaviviridae shared by tick-borne encephalitis virus (TBEV). It also possesses antiviral activity against two classical flaviviruses, yellow fever virus (YFV) and dengue virus (DENV), as well as a human coronavirus, HCoV-OC43, which is responsible for a significant share of common cold cases. It may not act on positive-strand RNA viruses indiscriminately. Moreover, TRIM56 is an interferon-inducible E3 ubiquitin ligase that modulates STING to confer double-stranded DNA-mediated innate immune responses. TRIM56 belongs to the C-V subclass of the TRIM (tripartite motif) family of proteins that are defined by an N-terminal RBCC (RING, Bbox, and coiled coil) domain, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as an uncharacterized region positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1242777557 363 FQLCKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQGCPFCRTEI 408
Cdd:cd16584     1 FLACKICLEQLRAPKTLPCLHTYCQDCLAQLADGGRVRCPECRETV 46

RING finger, HC subclass, found in RING finger protein 10 (RNF10) and similar proteins; RNF10 is an E3 ubiquitin-protein ligase that interacts with mesenchyme Homeobox 2 (MEOX2) transcription factor, a regulator of the proliferation, differentiation and migration of vascular smooth muscle cells and cardiomyocytes; it enhances Meox2 activation of the p21 promoter. It also regulates the expression of myelin-associated glycoprotein (MAG) genes and is required for myelin production in Schwann cells of the peripheral nervous system. Moreover, RNF10 regulates retinoic acid-induced neuronal differentiation and the cell cycle exit of P19 embryonic carcinoma cells. RNF10 contains a C3HC4-type RING-HC finger and three putative nuclear localization signals.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1242777557 364 QLCKICAENDKDIRIEPCGHLLCTPCLTQW---QDSDGQGCPFC 404
Cdd:cd16536     1 PQCPICLEPPVAPRITRCGHIFCWPCILRYlslSEKKWRKCPIC 44

Modified RING finger, HC subclass (C3HC5-type), found in neuralized-like protein 1B (NEURL1B); NEURL1B, also known as neuralized-2 (NEUR2) or neuralized-like protein 3, is a mammalian homolog of the Drosophila neuralized (D-neu) protein. It functions as an E3 ubiquitin-protein ligase that interacts with and ubiquitinates Delta. Thus, it plays a role in the endocytic pathways for Notch signaling through working cooperatively with another E3 ligase, Mind bomb-1 (Mib1), in Delta endocytosis to hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs)-positive vesicles. NEURL1B contains two neuralized homology regions (NHRs) responsible for Neural-ligand interactions and a modified C3HC5-type RING-HC finger required for ubiquitin ligase activity. The C3HC5-type RING-HC finger is distinguished from typical C3HC4-type RING-HC finger due to the existence of the additional cysteine residue in the middle portion of the RING finger domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1242777557 366 CKICAENDKDIRIEPCGHL-LCTPCLTQWQDSDGQGCPFCRTEIK 409
Cdd:cd16786     5 CTVCFDSEVDTVIYTCGHMcLCNSCGLKLKRQINACCPICRRVIK 49

RING finger, H2 subclass, found in 43 kDa receptor-associated protein of the synapse (Rapsyn) and similar proteins; Rapsyn, also known as acetylcholine receptor (AChR)-associated 43 kDa protein or RING finger protein 205 (RNF205), is a 43 kDa postsynaptic protein that plays an essential role in the clustering and maintenance of AChR in the postsynaptic membrane of the motor endplate. AChRs enable the transport of rapsyn from the Golgi complex to the plasma membrane through a molecule-specific interaction. Rapsyn also mediates subsynaptic anchoring of protein kinase A (PKA) type I in close proximity to the postsynaptic membrane, which is essential for synapse maintenance. Its mutations in humans cause endplate AChR deficiency and myasthenic syndrome. Rapsyn contains an N-terminal myristoylation signal required for membrane association, seven tetratricopeptide repeats (TPRs) that subserve rapsyn self-association, a coiled-coil domain responsible for the binding of determinants within the long cytoplasmic loop of each AChR subunit, a C3H2C3-type RING-H2 finger that binds to the cytoplasmic domain of beta-dystroglycan and to S-NRAP and links rapsyn to the subsynaptic cytoskeleton, and a serine phosphorylation site.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1242777557 366 CKICAE--NDKDIRIE--PCGHLLCTPCLTQWQDSDGQGCPFCR 405
Cdd:cd16478     4 CGMCGEsiGEKNEQLQalPCSHIFHLKCLQTNLRGGTRGCPNCR 47

RING finger, HC subclass, found in tripartite motif-containing protein 69 (TRIM69) and similar proteins; TRIM69, also known as RFP-like domain-containing protein trimless or RING finger protein 36 (RNF36), is a testis E3 ubiquitin-protein ligase that plays a specific role in apoptosis and may also play an important role in germ cell homeostasis during spermatogenesis. TRIM69 belongs to the C-IV subclass of the TRIM (tripartite motif) family of proteins that are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1242777557 366 CKICAENDKDIRIEPCGHLLCTPCLTQWQDSDGQG--CPFCRTEIKG 410
Cdd:cd16611     7 CPLCLDFFRDPVMLSCGHNFCQSCITGFWELQAEDttCPECRELCQY 53

RING finger, H2 subclass, found in protein E3 ubiquitin-protein ligase Praja-1, Praja-2, and similar proteins; This family includes two highly similar E3 ubiquitin-protein ligases, Praja-1 and Praja-2. Praja-1, also known as RING finger protein 70, is a RING-H2 finger ubiquitin ligase encoded by gene PJA1, a novel human X chromosome gene abundantly expressed in the brain. It has been implicated in bone and liver development, as well as memory formation and X-linked mental retardation (MRX). Praja-1 interacts with and activates the ubiquitin-conjugating enzyme UbcH5B, and shows E2-dependent E3 ubiquitin ligase activity. It is a 3-deazaneplanocin A (DZNep)-induced ubiquitin ligase that directly ubiquitinates individual polycomb repressive complex 2 (PRC2) subunits in a cell free system, which leads to their proteasomal degradation. It also plays an important role in neuronal plasticity, which is the basis for learning and memory. Moreover, Praja-1 ubiquitinates embryonic liver fodrin (ELF) and Smad3, but not Smad4, in a transforming growth factor-beta (TGF-beta)-dependent manner. It controls ELF abundance through ubiquitin-mediated degradation, and further regulates TGF-beta signaling, which plays a key role in the suppression of gastric carcinoma. Praja-1 also regulates the transcription function of the homeodomain protein Dlx5 by controlling the stability of Dlxin-1, via a ubiquitin-dependent degradation pathway. Praja-2, also known as RING finger protein 131, NEURODAP1, or KIAA0438, is an E2-dependent E3 ubiquitin ligase that interacts with and activates the ubiquitin-conjugating enzyme UbcH5B. It functions as an A-kinase anchoring protein (AKAP)-like E3 ubiquitin ligase that plays a critical role in controlling cyclic AMP (cAMP)-dependent PKA activity and pro-survival signaling, and further promotes cell proliferation and growth. Praja-2 is also involved in protein sorting at the postsynaptic density region of axosomatic synapses and possibly plays a role in synaptic communication and plasticity. Together with the AMPK-related kinase SIK2 and the CDK5 activator CDK5R1/p35, it forms a SIK2-p35-PJA2 complex that plays an essential role for glucose homeostasis in pancreatic beta cell functional compensation. Praja-2 ubiquitylates and degrades Mob, a core component of NDR/LATS kinase and a positive regulator of the tumor-suppressor Hippo signaling. Both Praja-1 and Praja-2 contain a potential nuclear localization signal (NLS) and a C-terminal C3H2C3-type RING-H2 motif.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1242777557 366 CKICAEN---DKDIRIEPCGHLLCTPCLTQWQDSDGQgCPFCR 405
Cdd:cd16465     2 CPICCSEyvkDEIATELPCHHLFHKPCITAWLQKSGT-CPVCR 43

RING finger, HC subclass, found in Arabidopsis thaliana protein XB3 homolog 1 (XBAT31) and similar proteins; XBAT31, also called ankyrin repeat domain and RING finger-containing protein XBAT31, or RING-type E3 ubiquitin transferase XB31, has no E3 ubiquitin-protein ligase activity observed when associated with the E2 enzyme UBC8 in vitro. XBAT31 contains a typical C3HC4-type RING-HC finger.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1242777557 361 STFQLCKICAENDKDIRIEPCGHLLCTPCL----------TQWQDSDGQGCPFCRTEI 408
Cdd:cd23144     4 SDEDVCCICFEHLCTIEIKDCGHQMCATCAlklcchnkpnPSSSPPRPPACPFCRQDI 61

RING finger, HC subclass, found in SH3 domain-containing RING finger protein 2 (SH3RF2) and similar proteins; SH3RF2, also known as heart protein phosphatase 1-binding protein (HEPP1), plenty of SH3s (POSH)-eliminating RING protein (POSHER), protein phosphatase 1 regulatory subunit 39, or RING finger protein 158 (RNF158), is a putative E3 ubiquitin-protein ligase that acts as an anti-apoptotic regulator for the c-Jun N-terminal kinase (JNK) pathway by binding to and promoting the proteasomal degradation of SH3RF1 (or POSH), a scaffold protein that is required for pro-apoptotic JNK activation. It may also play a role in cardiac functions together with protein phosphatase 1. SH3RF2 contains an N-terminal C3HC4-type RING-HC finger responsible for the E3 ligase activity and four Src Homology 3 (SH3) domains, which are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1242777557 366 CKICAEN-DKDIRIEPCGHLLCTPCLTQWQDSDGQ-GCPFCRT 406
Cdd:cd16749     3 CPVCFEKlDVTAKVLPCQHTFCKPCLQRIFKARKElRCPECRT 45

RING finger, HC subclass, found in Caenorhabditis elegans BRCA1-associated RING domain protein 1 (CeBARD1) and similar proteins; CeBARD1, also called Ce-BRD-1, Cebrd-1, or RING-type E3 ubiquitin transferase BARD1, is a constituent of the CeBCD complex that possesses E3 ubiquitin-protein ligase activity. It plays a role in triggering cellular responses at damage sites in response to DNA damage that may be induced by ionizing radiation. It protects against chromosome non-disjunction and nuclear fragmentation during meiotic double-strand break repair to ensure sister chromatid recombination and aid chromosome stability. CeBARD1 contains a typical C3HC4-type RING-HC finger.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1242777557 363 FQLCKICAENDKDI-RIEPCGHLLCTPCLTQWQDSDGQgCPFCRTEI 408
Cdd:cd23143     1 LIECVICSEPQIDTfLLSSCGHIYCWECFTEFIEKRHM-CPSCRFPL 46