EF-hand, calcium binding motif; A diverse superfamily of calcium sensors and calcium signal modulators; most examples in this alignment model have 2 active canonical EF hands. Ca2+ binding induces a conformational change in the EF-hand motif, leading to the activation or inactivation of target proteins. EF-hands tend to occur in pairs or higher copy numbers.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 40254415  91 KLRWYFKLYDVDGNGCIDRDELLTIIQAIRAInpcsdttmTAEEFTDTVFSKIDVNGDGELSLEEFIEGVQ 161
Cdd:cd00051   1 ELREAFRLFDKDGDGTISADELKAALKSLGEG--------LSEEEIDEMIREVDKDGDGKIDFEEFLELMA 63

XopAW family type III secretion system calcium-binding effector;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415   54 QYVEQMFETFDFNKDGYIDFMEYVAALSLVLKGKVEQKLRWYFKLYDVDGNGCIDRDELltiIQAIRAINPCSDtTMTAE 133
Cdd:NF041410  27 QFQKQLFAKLDSDGDGSVSQDELSSALSSKSDDGSLIDLSELFSDLDSDGDGSLSSDEL---AAAAPPPPPPPD-QAPST 102

                         90       100       110
                 ....*....|....*....|....*....|....*.
gi 40254415  134 EFTDTVFSKIDVNGDGELSLEEFIEGVQKDQMLLDT 169
Cdd:NF041410 103 ELADDLLSALDTDGDGSISSDELSAGLTSAGSSADS 138

XopAW family type III secretion system calcium-binding effector;

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 40254415   85 KGKVEQKLrwyFKLYDVDGNGCIDRDELLTiiqairAINPCSDTTMTAEefTDTVFSKIDVNGDGELSLEEF 156
Cdd:NF041410  25 SQQFQKQL---FAKLDSDGDGSVSQDELSS------ALSSKSDDGSLID--LSELFSDLDSDGDGSLSSDEL 85

EF-hand, calcium binding motif; A diverse superfamily of calcium sensors and calcium signal modulators; most examples in this alignment model have 2 active canonical EF hands. Ca2+ binding induces a conformational change in the EF-hand motif, leading to the activation or inactivation of target proteins. EF-hands tend to occur in pairs or higher copy numbers.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 40254415  91 KLRWYFKLYDVDGNGCIDRDELLTIIQAIRAInpcsdttmTAEEFTDTVFSKIDVNGDGELSLEEFIEGVQ 161
Cdd:cd00051   1 ELREAFRLFDKDGDGTISADELKAALKSLGEG--------LSEEEIDEMIREVDKDGDGKIDFEEFLELMA 63

EF-hand domain pair;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 40254415    89 EQKLRWYFKLYDVDGNGCIDRDELLTIIQAIRAINPCSDttmtaeEFTDTVFSKIDVNGDGELSLEEFIEGVQ 161
Cdd:pfam13499   1 EEKLKEAFKLLDSDGDGYLDVEELKKLLRKLEEGEPLSD------EEVEELFKEFDLDKDGRISFEEFLELYS 67

EF-hand, calcium binding motif, found in reticulocalbin-2 (RCN2) mainly from protostomes; This family corresponds to a group of uncharacterized RCN2-like proteins, which are mainly found in protostomes. Although their biological function remains unclear, they show high sequence similarity with RCN2 (also known as E6BP or TCBP-49), which is an endoplasmic reticulum resident low-affinity Ca2+-binding protein that has been implicated in immunity, redox homeostasis, cell cycle regulation and coagulation. Members in this family contain six copies of the EF-hand Ca2+-binding motif, but may lack a C-terminal His-Asp-Glu-Leu (HDEL) tetrapeptide that is required for retention of RCN2 in the endoplasmic reticulum (ER).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  32 GQLTLYEFRQFFGLKNLsPSASQY-VEQMFETFDFNKDGYIDFMEYVAALslvlkgKVEQKLRWYF-------KLYDVDG 103
Cdd:cd16227 137 GKLDKTEFSAFQHPEEY-PHMHPVlIEQTLRDKDKDNDGFISFQEFLGDR------AGHEDKEWLLvekdrfdEDYDKDG 209

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 40254415 104 NGCIDRDELLT-IIQairainpcsDTTMTAEEFTDTVFSKIDVNGDGELSLEEFIE 158
Cdd:cd16227 210 DGKLDGEEILSwLVP---------DNEEIAEEEVDHLFASADDDHDDRLSFDEILD 256

calmodulin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415   59 MFETFDFNKDGYIDFMEYVAALSLVLK-GKVEQKLRWYFKLYDVDGNGCIDRDELLTIIQAIrainpcsDTTMTAEEfTD 137
Cdd:PTZ00184  52 MINEVDADGNGTIDFPEFLTLMARKMKdTDSEEEIKEAFKVFDRDGNGFISAAELRHVMTNL-------GEKLTDEE-VD 123

                         90       100
                 ....*....|....*....|
gi 40254415  138 TVFSKIDVNGDGELSLEEFI 157
Cdd:PTZ00184 124 EMIREADVDGDGQINYEEFV 143

EF-hand, calcium binding motif, found in secretagogin (SCGN); SCGN is a six EF-hand calcium-binding protein expressed in neuroendocrine, pancreatic endocrine and retinal cells. It plays a crucial role in cell apoptosis, receptor signaling and differentiation. It is also involved in vesicle secretion through binding to various proteins, including interacts with SNAP25, SNAP23, DOC2alpha, ARFGAP2, rootletin, KIF5B, beta-tubulin, DDAH-2, ATP-synthase and myeloid leukemia factor 2. SCGN functions as a calcium sensor/coincidence detector modulating vesicular exocytosis of neurotransmitters, neuropeptides or hormones. It also serves as a calcium buffer in neurons. Thus, SCGN may be linked to the pathogenesis of neurological diseases such as Alzheimer's, and also acts as a serum marker of neuronal damage, or as a tumor biomarker. SCGN consists of the three globular domains each of which contains a pair of EF-hand motifs. All six EF hand motifs of SCGN in some eukaryotes, including D. rerio, X. laevis, M. domestica, G. gallus, O. anatinus, could potentially bind six calcium ions. In contrast, SCGNs from higher eukaryotes have at least one non-functional EF-hand motif due to the mutation(s) or deletions. For instance, the EF1 loop does not coordinate calcium ion due to the key residue asparagine replaced by lysine in SCGNs of many mammalian species. Moreover, the EF2 loop seems to be competent for calcium-binding in most mammalian SCGNs except for human and chimpanzee orthologs.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  14 SSTECHQWYKKFMTECpSGQLTLYEFRQFfgLKNL---------SPSASQYVEQMFETFDFNKDGYIDFMEYVAALSL-- 82
Cdd:cd16178  90 SSVEFMRIWRKYDADS-SGYISAAELKNF--LRDLflqhkkvitEDKLDEYTDTMMKIFDKNKDGRLDLNDMARILALqe 166

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  83 -------VLKGKVEQKLRWY---FKLYDVDGNGCIDRDELLTIIQAIRAINPCSDTTMTAEEFTDTVFSKIDVNGDGELS 152
Cdd:cd16178 167 nfllqfkMDAMSEEERKRDFekiFAHYDVSKTGALEGPEVDGFVKDMMELVKPSISGVQLDKFKEIILNHCDVNKDGKIQ 246

                ...
gi 40254415 153 LEE 155
Cdd:cd16178 247 KSE 249

centrin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415   60 FETFDFNKDGYIDFME-YVAALSLVLKGKVEQkLRWYFKLYDVDGNGCIDRDELLTII--------------QAIRAINP 124
Cdd:PTZ00183  23 FDLFDTDGSGTIDPKElKVAMRSLGFEPKKEE-IKQMIADVDKDGSGKIDFEEFLDIMtkklgerdpreeilKAFRLFDD 101

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 40254415  125 cSDT-----------------TMTAEEFTDTVfSKIDVNGDGELSLEEFIEGVQKD 163
Cdd:PTZ00183 102 -DKTgkislknlkrvakelgeTITDEELQEMI-DEADRNGDGEISEEEFYRIMKKT 155

Penta-EF hand, calcium binding motifs, found in Group I PEF proteins; The family corresponds to Group I PEF proteins that have been found not only in higher animals but also in lower animals, plants, fungi and protists. Group I PEF proteins include apoptosis-linked gene 2 protein (ALG-2), peflin and similar proteins. ALG-2, also termed programmed cell death protein 6 (PDCD6), is a widely expressed calcium-binding modulator protein associated with cell proliferation and death, as well as cell survival. It forms a homodimer in the cell or a heterodimer with its closest paralog peflin. Among the PEF proteins, ALG-2 can bind three Ca2+ ions through its EF1, EF3, and EF5 hands, where it is unique in that its EF5 hand binds Ca2+ ion in a canonical coordination. Peflin is a ubiquitously expressed 30-kD PEF protein containing five EF-hand motifs in its C-terminal domain and a longer N-terminal hydrophobic domain (NHB domain) than any other member of the PEF family. The NHB domain harbors nine repeats of a nonapeptide (A/PPGGPYGGP). Peflin may modulate the function of ALG-2 in Ca2+ signaling. It exists only as a heterodimer with ALG-2, and binds two Ca2+ ions through its EF1 and EF3 hands. Its additional EF5 hand is unpaired and does not bind Ca2+ ion but mediates the heterodimerization with ALG-2. The dissociation of heterodimer occurs in the presence of Ca2+.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  31 SGQLTLYEFRQFFglknlspsasQYVEQM---FETFDFNKDGYIDFMEYVAALS---LVLKgkvEQKLRWYFKLYDVDGN 104
Cdd:cd16180  51 SGTINFDEFVGLW----------KYIQDWrrlFRRFDRDRSGSIDFNELQNALSsfgYRLS---PQFVQLLVRKFDRRRR 117

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 40254415 105 GCIDRD---ELLTIIQairainpcsdtTMTaeeftdTVFSKIDVNGDG--ELSLEEFIEGV 160
Cdd:cd16180 118 GSISFDdfvEACVTLK-----------RLT------DAFRKYDTNRTGyaTISYEDFLTMV 161

EF-hand, calcium binding motif, found in the hexa-EF hand proteins family; The hexa-EF hand proteins family, also named the calbindin sub-family, contains a group of six EF-hand Ca2+-binding proteins, including calretinin (CR, also termed 29 kDa calbindin), calbindin D28K (CB, also termed vitamin D-dependent calcium-binding protein, avian-type), and secretagogin (SCGN). CR is a cytosolic hexa-EF-hand calcium-binding protein predominantly expressed in a variety of normal and tumorigenic t-specific neurons of the central and peripheral nervous system. It is a multifunctional protein implicated in many biological processes, including cell proliferation, differentiation, and cell death. CB is highly expressed in brain tissue. It is a strong calcium-binding and buffering protein responsible for preventing a neuronal death as well as maintaining and controlling calcium homeostasis. SCGN is a six EF-hand calcium-binding protein expressed in neuroendocrine, pancreatic endocrine and retinal cells. It plays a crucial role in cell apoptosis, receptor signaling and differentiation. It is also involved in vesicle secretion through binding to various proteins, including interacts with SNAP25, SNAP23, DOC2alpha, ARFGAP2, rootletin, KIF5B, beta-tubulin, DDAH-2, ATP-synthase and myeloid leukemia factor 2. SCGN functions as a Ca2+ sensor/coincidence detector modulating vesicular exocytosis of neurotransmitters, neuropeptides or hormones. Although the family members share a significant amount of secondary sequence homology, they display altered structural and biochemical characteristics, and operate in distinct fashions. CB contains six EF-hand motifs in a single globular domain, where EF-hands 1, 3, 4, 5 bind four calcium ions. CR contains six EF-hand motifs within two independent domains, CR I-II and CR III-VI. They harbor two and four EF-hand motifs, respectively. The first 5 EF-hand motifs are capable of binding calcium ions, while the EF-hand 6 is inactive. SCGN consists of the three globular domains each of which contains a pair of EF-hand motifs. Human SCGN simultaneously binds four calcium ions through its EF-hands 3, 4, 5 and 6 in one high affinity and three low affinity calcium-binding sites. In contrast, SCGNs in other lower eukaryotes, such as D. rerio, X. laevis, M. domestica, G. gallus, O. anatinus, are fully competent in terms of six calcium-binding.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  39 FRQFFGLKNLSPSASQYVEQMFETF----DFNKDGYIDFMEYVAAL----SLVLKGKVEQKLRW------YFKLYDVDGN 104
Cdd:cd15902  25 LRELLKALNGKDKTDDEVAEKKKEFmekyDENEDGKIEIRELANILpteeNFLLLFRREQPLISsvefmkIWRKYDTDGS 104

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415 105 GCIDRDELLTIIQAIRAINPCSDTTMTAEEFTDTVFSKIDVNGDGELSLEEFIE--GVQ-----KDQMLLDTLTRSLDLT 177
Cdd:cd15902 105 GFIEAKELKGFLKDLLLKNKKHVSPPKLDEYTKLILKEFDANKDGKLELDEMAKllPVQenfllKFQILGAMDLTKEDFE 184

                ..
gi 40254415 178 RI 179
Cdd:cd15902 185 KV 186

EF-hand, calcium binding motif, found in apoptosis-linked gene 2 protein (ALG-2) and similar proteins; ALG-2, also termed programmed cell death protein 6 (PDCD6), or probable calcium-binding protein ALG-2, is one of the prototypic members of the penta EF-hand protein family. It is a widely expressed calcium-binding modulator protein associated with cell proliferation and death, as well as cell survival. ALG-2 acts as a pro-apoptotic factor participating in T cell receptor-, Fas-, and glucocorticoid-induced programmed cell death, and also serves as a useful molecular marker for the prognosis of cancers. Moreover, ALG-2 functions as a calcium ion sensor at endoplasmic reticulum (ER) exit sites, and modulates ER-stress-stimulated cell death and neuronal apoptosis during organ formation. Furthermore, ALG-2 can mediate the pro-apoptotic activity of cisplatin or tumor necrosis factor alpha (TNFalpha) through the down-regulation of nuclear factor-kappaB (NF-kappaB) expression. It also inhibits angiogenesis through PI3K/mTOR/p70S6K pathway by interacting of vascular endothelial growth factor receptor-2 (VEGFR-2). In addition, nuclear ALG-2 may participate in the post-transcriptional regulation of Inositol Trisphosphate Receptor Type 1 (IP3R1) pre-mRNA at least in part by interacting with CHERP (Ca2+ homeostasis endoplasmic reticulum protein) calcium-dependently. ALG-2 contains five serially repeated EF-hand motifs and interacts with various proteins, including ALG-2-interacting protein X (Alix), Fas, annexin XI, death-associated protein kinase 1 (DAPk1), Tumor susceptibility gene 101 (TSG101), Sec31A, phospholipid scramblase 3 (PLSCR3), the P-body component PATL1, and endosomal sorting complex required for transport (ESCRT)-III-related protein IST1, in a calcium-dependent manner. It forms a homodimer in the cell or a heterodimer with its closest paralog peflin. Among the PEF proteins, ALG-2 can bind three Ca2+ ions through its EF1, EF3, and EF5 hands, where it is unique in that its EF5 hand binds Ca2+ ion in a canonical coordination.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  31 SGQLTLYEFRQFFGLKNLSPSASQYVEQMFETFDFNKDGYIDFMEYvAALslvlkGKVEQKLRWYFKLYDVDGNGCIDRD 110
Cdd:cd16183  14 SGQISATELQQALSNGTWTPFNPETVRLMIGMFDRDNSGTINFQEF-AAL-----WKYITDWQNCFRSFDRDNSGNIDKN 87

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 40254415 111 ELLTIIQAI--RainpCSDttmtaeEFTDTVFSKIDVNGDGELSLEEFIEGVqkdqMLLDTLTRS 173
Cdd:cd16183  88 ELKQALTSFgyR----LSD------QFYDILVRKFDRQGRGTIAFDDFIQCC----VVLQTLTDS 138

EF-hand, calcium binding motif, found in uncharacterized calglandulin-like proteins; The family corresponds to a group of uncharacterized calglandulin-like proteins. Although their biological function remain unclear, they show high sequence similarity with human calglandulin-like protein GAGLP, which is an ortholog of calglandulin from the venom glands of Bothrops insularis snake. Both GAGLP and calglandulin are putative Ca2+-binding proteins with four EF-hand motifs. However, members in this family contain only three EF-hand motifs. In this point, they may belong to the parvalbumin-like EF-hand family, which is characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  70 YIDFMEYVAALSLvlKGKVEQKLRWYFKLYDVDGNGCIDRDELLTIIQAIRAINPCSDTTmtaEEFTDTVFSKIDVNGDG 149
Cdd:cd16252  19 YSKFFEYMQKFQT--SEQQEEAIRKAFQMLDKDKSGFIEWNEIKYILSTVPSSMPVAPLS---DEEAEAMIQAADTDGDG 93

                        90
                ....*....|...
gi 40254415 150 ELSLEEFIEGVQK 162
Cdd:cd16252  94 RIDFQEFSDMVKK 106

EF-hand, calcium binding motif, found in calumenin, reticulocalbin-1 (RCN-1), reticulocalbin-3 (RCN-3), and similar proteins; The family corresponds to a group of six EF-hand Ca2+-binding proteins, including calumenin (also known as crocalbin or CBP-50), reticulocalbin-1 (RCN-1), reticulocalbin-3 (RCN-3), and similar proteins. Calumenin is an endo/sarcoplasmic reticulum (ER/SR) resident low-affinity Ca2+-binding protein that contains six EF-hand domains and a C-terminal SR retention signal His-Asp-Glu-Phe (HDEF) tetrapeptide. It functions as a novel regulator of SERCA2, and its expressional changes are tightly coupled with Ca2+-cycling of cardiomyocytes. It is also broadly involved in haemostasis and in the pathophysiology of thrombosis. Moreover, the extracellular calumenin acts as a suppressor of cell migration and tumor metastasis. RCN-1 is an endoplasmic reticulum resident Ca2+-binding protein with a carboxyl-terminal His-Asp-Glu-Leu (HDEL) tetrapeptide signal. It acts as a potential negative regulator of B-RAF activation and can negatively modulate cardiomyocyte hypertrophy by inhibition of the mitogen-activated protein kinase signalling cascade. It also plays a key role in the development of doxorubicin-associated resistance. RCN-3 is a putative six EF-hand Ca2+-binding protein that contains five RXXR (X is any amino acid) motifs and a C-terminal ER retrieval signal HDEL tetrapeptide. The RXXR motif represents the target sequence of subtilisin-like proprotein convertases (SPCs). RCN-3 is specifically bound to the paired basic amino-acid-cleaving enzyme-4 (PACE4) precursor protein and plays an important role in the biosynthesis of PACE4.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  32 GQLTLYEFRQFfglknLSPSASQY-----VEQMFETFDFNKDGYIDFMEYVAalSLVLKGKVEQKLRW------YFKLY- 99
Cdd:cd16226 134 GKLTKEEFTAF-----LHPEEFPHmrdivVQETLEDIDKNKDGFISLEEYIG--DMYRDDDEEEDPDWvksereQFKEFr 206

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415 100 DVDGNGCIDRDElltiiqaIRA-INPcsDTTMTAEEFTDTVFSKIDVNGDGELSLEEFIE 158
Cdd:cd16226 207 DKNKDGKMDREE-------VKDwILP--EDYDHAEAEAKHLIYEADDDKDGKLTKEEILD 257

EF-hand, calcium binding motif, found in Drosophila melanogaster calbindin-32 (CBN) and similar proteins; CBN, the product of the cbn gene, is a Drosophila homolog to vertebrate neuronal six EF-hand calcium binding proteins. It is expressed through most of ontogenesis with a selective distribution in the nervous system and in a few small adult thoracic muscles. Its precise biological role remains unclear. CBN contains six EF-hand motifs, but some of them may not bind calcium ions due to the lack of key residues.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  36 LYEFRQFFGLKNLSPSA------SQYVEQMFETFDFNKDGYIDFMEYVAALSL------------VLKGKVEQKLRWyfK 97
Cdd:cd16179  25 LREFVSSVNPEDVGPEVvsetalEELKEEFMEAYDENQDGRIDIRELAQLLPTeenflllfrrdnPLDSSVEFMKVW--R 102

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 40254415  98 LYDVDGNGCIDRDEL----LTIIQAIRAINPCSDTTMTaeEFTDTVFSKIDVNGDGELSLEE 155
Cdd:cd16179 103 EYDKDNSGYIEADELknflKHLLKEAKRDNDVSEDKLI--EYTDTILQLFDRNKDGKLQLSE 162

EF-hand, extracellular calcium-binding (EC) motif, found in secreted protein acidic and rich in cysteine (SPARC)-like proteins; The SPARC protein family represents a diverse group of proteins that share a follistatin-like (FS) domain and an extracellular calcium-binding (EC) domain with two EF-hand motifs. It includes SPARC (for secreted protein acidic and rich in cysteine, also termed osteonectin/ON, or basement-membrane protein 40/BM-40), SPARC-like protein 1 (for secreted protein, acidic and rich in cysteines-like 1/ SPARCL1, also termed high endothelial venule protein/Hevi, or MAST 9, or SC-1, or RAGS-1, or QR1, or ECM 2), testicans 1, 2, and 3 (also termed SPARC/osteonectin, CWCV, and Kazal-like domains proteoglycans, or SPOCK), secreted modular calcium-binding protein SMOC-1 (also termed SPARC-related modular calcium-binding protein 1) and SMOC-2 (also termed SPARC-related modular calcium-binding protein 2, or smooth muscle-associated protein 2/SMAP-2), follistatin-related protein 1 (FRP-1, also termed follistatin-like protein 1/fstl-1, TSC-36/Flik, TGF-beta inducible protein). The SPARC proteins have been implicated in modulating cell interaction with the extracellular milieu, including regulation of extracellular matrix assembly and deposition, counter-adhesion, effects on extracellular protease activity, and modulation of growth factor/cytokine signaling pathways, as well as in development and disease.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  89 EQKLRWYFKLYDVDGNGCIDRDELLTIIQAIRAINPCSDttmtaeEFTDTVfskiDVNGDGELSLEEFIE 158
Cdd:cd00252  44 KEIAQWEFDNLDNNKDGKLDKRELAPFRAPLMPLEHCAR------GFFESC----DLNKDKKISLQEWLG 103

EF-hand-like motif found in the dystrophin/dystrobrevin/dystrotelin family; The dystrophin/dystrobrevin/dystrotelin family has been characterized by a compact cluster of domains comprising four EF-hand-like motifs and a ZZ-domain, followed by a looser region with two coiled-coils. Dystrophin is the founder member of this family. It is a sub-membrane cytoskeletal protein associated with the inner surface membrane. Dystrophin and its close paralog utrophin have a large N-terminal extension of actin-binding CH domains, up to 24 spectrin repeats, and a WW domain. Its further paralog, dystrophin-related protein 2 (DRP-2), retains only two of the spectrin repeats. Dystrophin, utrophin or DRP2 can form the core of a membrane-bound complex consisting of dystroglycan, sarcoglycans and syntrophins, known as the dystrophin-glycoprotein complex (DGC) that plays an important role in brain development and disease, as well as in the prevention of muscle damage. Dystrobrevins, including alpha- and beta-dystrobrevin, lack the large N-terminal extension found in dystrophin, but alpha-dystrobrevin has a characteristic C-terminal extension. Dystrobrevins are part of the DGC. They physically associate with members of the dystrophin family and with the syntrophins through their homologous C-terminal coiled coil motifs. In contrast, dystrotelins lack both the large N-terminal extension found in dystrophin and the obvious syntrophin-binding sites (SBSs). Dystrotelins are not critical for mammalian development. They may be involved in other forms of cytokinesis. Moreover, dystrotelin is unable to heterodimerize with members of the dystrophin or dystrobrevin families, or to homodimerize.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 40254415  59 MFETFDFNKDGYIDFMEYVAALSLVLKGKVEQKLRWYFKLYDvDGNGCIDRDELLTIIQAIRAI 122
Cdd:cd15901  59 LLNLYDRNRTGCIRLLSVKIALITLCAASLLDKYRYLFGQLA-DSSGFISRERLTQFLQDLLQI 121

EF-hand, calcium binding motif, found in CREC-EF hand family; The CREC (Cab45/reticulocalbin/ERC45/calumenin)-EF hand family contains a group of six EF-hand, low-affinity Ca2+-binding proteins, including reticulocalbin (RCN-1), ER Ca2+-binding protein of 55 kDa (ERC-55, also known as TCBP-49 or E6BP), reticulocalbin-3 (RCN-3), Ca2+-binding protein of 45 kDa (Cab45 and its splice variant Cab45b), and calumenin ( also known as crocalbin or CBP-50). The proteins are not only localized in various parts of the secretory pathway, but also found in the cytosolic compartment and at the cell surface. They interact with different ligands or proteins and have been implicated in the secretory process, chaperone activity, signal transduction as well as in a large variety of disease processes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  34 LTLYEFRQFfglknLSPSASQY-----VEQMFETFDFNKDGYIDFMEYVAALSLVLKGkvEQKLRW-------YFKLYDV 101
Cdd:cd15899 140 LTLEEFLAF-----LHPEESPYmldfvIKETLEDLDKNGDGFISLEEFISDPYSADEN--EEEPEWvkvekerFVELRDK 212

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 40254415 102 DGNGCIDRDELLTIIQairainpcSDTTMTAEEFTDTVFSKIDVNGDGELSLEEFIE 158
Cdd:cd15899 213 DKDGKLDGEELLSWVD--------PSNQEIALEEAKHLIAESDENKDGKLSPEEILD 261

Penta-EF hand, calcium binding motifs, found in PEF calpain family; The PEF calpain family belongs to the second group of penta-EF hand (PEF) proteins. It includes classical (also called conventional or typical) calpain (referring to a calcium-dependent papain-like enzymes, EC 3.4.22.17) large catalytic subunits (CAPN1, 2, 3, 8, 9, 11, 12, 13, 14) and two calpain small subunits (CAPNS1 and CAPNS2), which are largely confined to animals (metazoans). These PEF-containing are nonlysosomal intracellular calcium-activated intracellular cysteine proteases that play important roles in the degradation or functional modulation in a variety of substrates in response to calcium signalling. The classical mu- and m-calpains are heterodimers consisting of homologous but a distinct (large) L-subunit/chain (CAPN1 or CAPN2) and a common (small) S-subunit/chain (CAPNS1 or CAPNS2). These L-subunits (CAPN1 and CAPN2) and S-subunit CAPNS1 are ubiquitously found in all tissues. Other calpains likely consist of an isolated L-subunit/chain alone. Many of them, such as CAPNS2, CAPN3 (in skeletal muscle, or lens), CAPN8 (in stomach), CAPN9 (in digestive tracts), CAPN11 (in testis), CAPN12 (in follicles), are tissue-specific and have specific functions in distinct organs. The L-subunits of similar structure (called CALPA and B) also have been found in Drosophila melanogaster. The S-subunit seems to have a chaperone-like function for proper folding of the L-subunit. The catalytic L-subunits contain a short N-terminal anchor helix, followed by a calpain cysteine protease (CysPc) domain, a C2-domain-like (C2L) domain, and a C-terminal Ca2+-binding penta-EF-hand (PEF) domain. The S-subunits only have the PEF domain following an N-terminal Gly-rich hydrophobic domain. The calpains undergo a rearrangement of the protein backbone upon Ca2+-binding.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  58 QMFETFDFNKDGYIDFMEYvaalsLVLKGKVeQKLRWYFKLYDVDGNGCIDRDELLTIIQAI------RAIN------PC 125
Cdd:cd16182  46 SLIALMDTNGSGRLDLEEF-----KTLWSDL-KKWQAIFKKFDTDRSGTLSSYELRKALESAgfhlsnKVLQalvlryAD 119

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*.
gi 40254415 126 SDTTMTAEEFTD---------TVFSKIDVNGDG--ELSLEEFIEGV 160
Cdd:cd16182 120 STGRITFEDFVSclvrlktafETFSALDKKNEGviPLTLEEWLLLT 165

EF-hand, calcium binding motif; EF-hands are calcium-binding motifs that occur at least in pairs. Links between disease states and genes encoding EF-hands, particularly the S100 subclass, are emerging. Each motif consists of a 12 residue loop flanked on either side by a 12 residue alpha-helix. EF-hands undergo a conformational change unpon binding calcium ions.

                           10        20
                   ....*....|....*....|....*....
gi 40254415     91 KLRWYFKLYDVDGNGCIDRDELLTIIQAI 119
Cdd:smart00054   1 ELKEAFRLFDKDGDGKIDFEEFKDLLKAL 29

EF-hand motif found in eukaryotic phosphoinositide-specific phospholipase C (PI-PLC, EC 3.1.4.11) isozymes; PI-PLC isozymes are signaling enzymes that hydrolyze the membrane phospholipids phosphatidylinositol-4,5-bisphosphate (PIP2) to generate two important second messengers in eukaryotic signal transduction cascades, Inositol 1,4,5-trisphosphate (InsP3) and diacylglycerol (DAG). InsP3 triggers inflow of calcium from intracellular stores, while DAG, together with calcium, activates protein kinase C, which goes on to phosphorylate other molecules, leading to altered cellular activity. Calcium is required for the catalysis. This family corresponds to the four EF-hand motifs containing PI-PLC isozymes, including PI-PLC-beta (1-4), -gamma (1-2), -delta (1,3,4), -epsilon (1), -zeta (1), eta (1-2). Lower eukaryotes such as yeast and slime molds contain only delta-type isozymes. In contrast, other types of isoforms present in higher eukaryotes. This family also includes 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase 1 (PLC1) from fungi. Some homologs from plants contain only two atypical EF-hand motifs and they are not included. All PI-PLC isozymes except sperm-specific PI-PLC-zeta share a core set of domains, including an N-terminal pleckstrin homology (PH) domain, four atypical EF-hand motifs, a PLC catalytic core, and a single C2 domain. PI-PLC-zeta lacks the PH domain. The PLC catalytic core domain is a TIM barrel with two highly conserved regions (X and Y) split by a highly degenerate linker sequence. Most of EF-hand motifs found in PI-PLCs consist of a helix-loop-helix structure, but lack residues critical to metal binding. Moreover, the EF-hand region of most of PI-PLCs may have an important regulatory function, but it has yet to be identified. However, PI-PLC-zeta is a key exception. It is responsible for Ca2+ oscillations in fertilized oocytes and exhibits a high sensitivity to Ca2+ mediated through its EF-hand domain. In addition, PI-PLC-eta2 shows a canonical EF-loop directing Ca2+-sensitivity and thus can amplify transient Ca2+ signals. Also it appears that PI-PLC-delta1 can regulate the binding of PH domain to PIP2 in a Ca2+-dependent manner through its functionally important EF-hand domains. PI-PLCs can be activated by a variety of extracellular ligands, such as growth factors, hormones, cytokines and lipids. Their activation has been implicated in tumorigenesis and/or metastasis linked to migration, proliferation, growth, inflammation, angiogenesis and actin cytoskeleton reorganization. PI-PLC-beta isozymes are activated by G-protein coupled receptor (GPCR) through different mechanisms. However, PI-PLC-gamma isozymes are activated by receptor tyrosine kinase (RTK), such as Rho and Ras GTPases. In contrast, PI-PLC-epsilon are activated by both GPCR and RTK. PI-PLC-delta1 and PLC-eta 1 are activated by GPCR-mediated calcium mobilization. The activation mechanism for PI-PLC-zeta remains unclear.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 40254415  91 KLRWYFKLYDVDGNGCIDRDELLTIIQairAINPCSDTTMTAEeftdtVFSKIDVNGDGELSLEEFIE 158
Cdd:cd15898   1 WLRRQWIKADKDGDGKLSLKEIKKLLK---RLNIRVSEKELKK-----LFKEVDTNGDGTLTFDEFEE 60

EF-hand, calcium binding motif; EF-hands are calcium-binding motifs that occur at least in pairs. Links between disease states and genes encoding EF-hands, particularly the S100 subclass, are emerging. Each motif consists of a 12 residue loop flanked on either side by a 12 residue alpha-helix. EF-hands undergo a conformational change unpon binding calcium ions.

                           10        20
                   ....*....|....*....|....*.
gi 40254415     56 VEQMFETFDFNKDGYIDFMEYVAALS 81
Cdd:smart00054   2 LKEAFRLFDKDGDGKIDFEEFKDLLK 27

EF-hand, calcium binding motif, found in CREC-EF hand family; The CREC (Cab45/reticulocalbin/ERC45/calumenin)-EF hand family contains a group of six EF-hand, low-affinity Ca2+-binding proteins, including reticulocalbin (RCN-1), ER Ca2+-binding protein of 55 kDa (ERC-55, also known as TCBP-49 or E6BP), reticulocalbin-3 (RCN-3), Ca2+-binding protein of 45 kDa (Cab45 and its splice variant Cab45b), and calumenin ( also known as crocalbin or CBP-50). The proteins are not only localized in various parts of the secretory pathway, but also found in the cytosolic compartment and at the cell surface. They interact with different ligands or proteins and have been implicated in the secretory process, chaperone activity, signal transduction as well as in a large variety of disease processes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  52 ASQYVEQMFETFDFNKDGYIDFMEY-VAALSLVLKG---------------KVEQKLRWYFKLYDVDGNGCIDRDELLTI 115
Cdd:cd15899  69 AMEESKEQFRAVDPDEDGHVSWDEYkNDTYGSVGDDeenvadnikedeeykKLLLKDKKRFEAADQDGDLILTLEEFLAF 148

                        90       100       110       120
                ....*....|....*....|....*....|....*....|..
gi 40254415 116 IQAIRaiNPCSDTTMTAEEFTDtvfskIDVNGDGELSLEEFI 157
Cdd:cd15899 149 LHPEE--SPYMLDFVIKETLED-----LDKNGDGFISLEEFI 183

EF-hand domain pair;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 40254415    30 PSGQLTLYEFRQF---FGLKNLSPsasQYVEQMFETFDFNKDGYIDFMEYVAAL 80
Cdd:pfam13833   1 EKGVITREELKRAlalLGLKDLSE---DEVDILFREFDTDGDGYISFDEFCVLL 51

EF-hand, calcium binding motif, found in parvalbumin-like EF-hand family; The family includes alpha- and beta-parvalbumins, and a group of uncharacterized calglandulin-like proteins. Parvalbumins are small, acidic, cytosolic EF-hand-containing Ca2+-buffer and Ca2+ transporter/shuttle proteins belonging to EF-hand superfamily. They are expressed by vertebrates in fast-twitch muscle cells, specific neurons of the central and peripheral nervous system, sensory cells of the mammalian auditory organ (Corti's cell), and some other cells, and characterized by the presence of three consecutive EF-hand motifs (helix-loop-helix) called AB, CD, and EF, but only CD and EF can chelate metal ions, such as Ca2+ and Mg2+. Thus, they may play an additional role in Mg2+ handling. Moreover, parvalbumins represent one of the major animal allergens. In metal-bound states, parvalbumins possess a rigid and stable tertiary structure and display strong allergenicity. In contrast, the metal-free parvalbumins are intrinsically disordered, and the loss of metal ions results in a conformational change that decreases their IgE binding capacity. Furthermore, parvalbumins have been widely used as a neuronal marker for a variety of functional brain systems. They also function as a Ca2+ shuttle transporting Ca2+ from troponin-C (TnC) to the sarcoplasmic reticulum (SR) Ca2+ pump during muscle relaxation. Thus they may facilitate myocardial relaxation and play important roles in cardiac diastolic dysfunction. Parvalbumins consists of alpha- and beta- sublineages, which can be distinguished on the basis of isoelectric point (pI > 5 for alpha; pI

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  37 YEFRQFFGLKNLSPSASQYVEQMFETFDFNKDGYIDFMEyvaaLSLVLKG-------KVEQKLRWYFKLYDVDGNGCIDR 109
Cdd:cd16251  17 FNYKKFFEHVGLKQKSEDQIKKVFQILDKDKSGFIEEEE----LKYILKGfsiagrdLTDEETKALLAAGDTDGDGKIGV 92

                ....*....
gi 40254415 110 DELLTIIQA 118
Cdd:cd16251  93 EEFATLVAG 101

EF-hand, calcium binding motif, found in secretagogin (SCGN); SCGN is a six EF-hand calcium-binding protein expressed in neuroendocrine, pancreatic endocrine and retinal cells. It plays a crucial role in cell apoptosis, receptor signaling and differentiation. It is also involved in vesicle secretion through binding to various proteins, including interacts with SNAP25, SNAP23, DOC2alpha, ARFGAP2, rootletin, KIF5B, beta-tubulin, DDAH-2, ATP-synthase and myeloid leukemia factor 2. SCGN functions as a calcium sensor/coincidence detector modulating vesicular exocytosis of neurotransmitters, neuropeptides or hormones. It also serves as a calcium buffer in neurons. Thus, SCGN may be linked to the pathogenesis of neurological diseases such as Alzheimer's, and also acts as a serum marker of neuronal damage, or as a tumor biomarker. SCGN consists of the three globular domains each of which contains a pair of EF-hand motifs. All six EF hand motifs of SCGN in some eukaryotes, including D. rerio, X. laevis, M. domestica, G. gallus, O. anatinus, could potentially bind six calcium ions. In contrast, SCGNs from higher eukaryotes have at least one non-functional EF-hand motif due to the mutation(s) or deletions. For instance, the EF1 loop does not coordinate calcium ion due to the key residue asparagine replaced by lysine in SCGNs of many mammalian species. Moreover, the EF2 loop seems to be competent for calcium-binding in most mammalian SCGNs except for human and chimpanzee orthologs.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415  46 KNLSPSASQYVEQMF-ETFDFNKDGYIDFMEYVAAL-----SLVLKGKVEQKLR--------WyfKLYDVDGNGCIDRDE 111
Cdd:cd16178  36 DTISADEVQDVKECFmSAYDVTGDGRIQIQELANIIlpddeNFLLFFRREEPLDssvefmriW--RKYDADSSGYISAAE 113

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....
gi 40254415 112 LLTIIQAIRAINPCSDTTMTAEEFTDTVFSKIDVNGDGELSLEE 155
Cdd:cd16178 114 LKNFLRDLFLQHKKVITEDKLDEYTDTMMKIFDKNKDGRLDLND 157

EF-hand domain pair;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 40254415   103 GNGCIDRDELLTIIQAIRAinpcsdTTMTAEEFtDTVFSKIDVNGDGELSLEEFIEGVQK 162
Cdd:pfam13833   1 EKGVITREELKRALALLGL------KDLSEDEV-DILFREFDTDGDGYISFDEFCVLLER 53

EF-hand, calcium binding motif, found in the hexa-EF hand proteins family; The hexa-EF hand proteins family, also named the calbindin sub-family, contains a group of six EF-hand Ca2+-binding proteins, including calretinin (CR, also termed 29 kDa calbindin), calbindin D28K (CB, also termed vitamin D-dependent calcium-binding protein, avian-type), and secretagogin (SCGN). CR is a cytosolic hexa-EF-hand calcium-binding protein predominantly expressed in a variety of normal and tumorigenic t-specific neurons of the central and peripheral nervous system. It is a multifunctional protein implicated in many biological processes, including cell proliferation, differentiation, and cell death. CB is highly expressed in brain tissue. It is a strong calcium-binding and buffering protein responsible for preventing a neuronal death as well as maintaining and controlling calcium homeostasis. SCGN is a six EF-hand calcium-binding protein expressed in neuroendocrine, pancreatic endocrine and retinal cells. It plays a crucial role in cell apoptosis, receptor signaling and differentiation. It is also involved in vesicle secretion through binding to various proteins, including interacts with SNAP25, SNAP23, DOC2alpha, ARFGAP2, rootletin, KIF5B, beta-tubulin, DDAH-2, ATP-synthase and myeloid leukemia factor 2. SCGN functions as a Ca2+ sensor/coincidence detector modulating vesicular exocytosis of neurotransmitters, neuropeptides or hormones. Although the family members share a significant amount of secondary sequence homology, they display altered structural and biochemical characteristics, and operate in distinct fashions. CB contains six EF-hand motifs in a single globular domain, where EF-hands 1, 3, 4, 5 bind four calcium ions. CR contains six EF-hand motifs within two independent domains, CR I-II and CR III-VI. They harbor two and four EF-hand motifs, respectively. The first 5 EF-hand motifs are capable of binding calcium ions, while the EF-hand 6 is inactive. SCGN consists of the three globular domains each of which contains a pair of EF-hand motifs. Human SCGN simultaneously binds four calcium ions through its EF-hands 3, 4, 5 and 6 in one high affinity and three low affinity calcium-binding sites. In contrast, SCGNs in other lower eukaryotes, such as D. rerio, X. laevis, M. domestica, G. gallus, O. anatinus, are fully competent in terms of six calcium-binding.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 40254415  96 FKLYDVDGNGCIDRDELLTIIQA-IRAINPCSDTTMTAEEFTDTVFSKIDVNGDGELSLEEF 156
Cdd:cd15902   5 WMHFDADGNGYIEGKELDSFLRElLKALNGKDKTDDEVAEKKKEFMEKYDENEDGKIEIREL 66

EF-hand, calcium binding motif, found in calcium uptake protein 3, mitochondrial (MICU3) and similar proteins; MICU3, also termed EF-hand domain-containing family member A2 (EFHA2), is a paralog of MICU1 and notably found in the central nervous system (CNS) and skeletal muscle. At present, the precise molecular function of MICU3 remains unclear. It likely has a role in mitochondrial calcium handling. MICU3 contains an N-terminal mitochondrial targeting sequence (MTS) as well as two evolutionarily conserved canonical Ca2+-binding EF-hands separated by a long stretch of residues predicted to form alpha-helices.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*.
gi 40254415 120 RAINPCSDTTMTAEeFTDTVFSKIDVNGDGELSLEEFIeGVQKDQM 165
Cdd:cd16175  85 RAVKVCTGLKLSPH-LVNTVFKIFDVDGDGQLSYKEFI-GIMKDRL 128

EF-hand, calcium binding motif, found in mitochondrial calcium uptake proteins MICU1, MICU2, MICU3, and similar proteins; This family includes mitochondrial calcium uptake protein MICU1 and its two additional paralogs, MICU2 and MICU3. MICU1 localizes to the inner mitochondrial membrane (IMM). It functions as a gatekeeper of the mitochondrial calcium uniporter (MCU) and regulates MCU-mediated mitochondrial Ca2+ uptake, which is essential for maintaining mitochondrial homoeostasis. MICU1 and MICU2 are physically associated within the uniporter complex and are co-expressed across all tissues. They may play non-redundant roles in the regulation of the mitochondrial calcium uniporter. At present, the precise molecular function of MICU2 and MICU3 remain unclear. MICU2 may play possible roles in Ca2+ sensing and regulation of MCU, calcium buffering with a secondary impact on transport or assembly and stabilization of MCU. MICU3 likely has a role in mitochondrial calcium handling. All members in this family contains an N-terminal mitochondrial targeting sequence (MTS) as well as two evolutionarily conserved canonical Ca2+-binding EF-hands separated by a long stretch of residues predicted to form alpha-helices.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 40254415 107 IDRDELLtiiqaiRAINPCSDTTMTaEEFTDTVFSKIDVNGDGELSLEEFIeGVQKDQM 165
Cdd:cd15900 102 IDRKTFK------RAAKVVAGVELS-DHVVDVVFTIFDEDGDGILSHKEFI-SVMKDRL 152