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
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 76056882 306 ELRDAFREFDTNGDGEISTSELREAMRKLlGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMMS 369
Cdd:cd00051   1 ELREAFRLFDKDGDGTISADELKAALKSL-GEGLSEEEIDEMIREVDKDGDGKIDFEEFLELMA 63

EF-hand domain pair;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 76056882   305 KELRDAFREFDTNGDGEISTSELREAMRKLLGHQVGHRD-IEEIIRDVDLNGDGRVDFEEFVRMMS 369
Cdd:pfam13499   2 EKLKEAFKLLDSDGDGYLDVEELKKLLRKLEEGEPLSDEeVEELFKEFDLDKDGRISFEEFLELYS 67

centrin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882  221 SLRPEEIEELREAFREFDKDKDGYINCRDLGNCMRTMGYMPTEMELIELSQQINMNLGGHVDFDDFVELMGPKLlaetAD 300
Cdd:PTZ00183  10 GLTEDQKKEIREAFDLFDTDGSGTIDPKELKVAMRSLGFEPKKEEIKQMIADVDKDGSGKIDFEEFLDIMTKKL----GE 85

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882  301 MIGVKELRDAFREFDTNGDGEISTSELREAMRKlLGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMMSR 370
Cdd:PTZ00183  86 RDPREEILKAFRLFDDDKTGKISLKNLKRVAKE-LGETITDEELQEMIDEADRNGDGEISEEEFYRIMKK 154

Ca2+-binding protein, EF-hand superfamily [Signal transduction mechanisms];

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 225 EEIEELREAFREFDKDKDGYINCRDLGNCMRTMgymptemeLIELSQQINMNLGGHVDFDDFVELMGPKLLAETADmigv 304
Cdd:COG5126   2 LQRRKLDRRFDLLDADGDGVLERDDFEALFRRL--------WATLFSEADTDGDGRISREEFVAGMESLFEATVEP---- 69

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 76056882 305 kELRDAFREFDTNGDGEISTSELREAMRkllGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMM 368
Cdd:COG5126  70 -FARAAFDLLDTDGDGKISADEFRRLLT---ALGVSEEEADELFARLDTDGDGKISFEEFVAAV 129

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 76056882 211 MLSSAFGQDRSLR--PEE-------IEELREAFREFDKDKDGYINCRDLGNCMRTMGYmptemeliELSQQINMNL---- 277
Cdd:cd16180  41 LMINMFDRDRSGTinFDEfvglwkyIQDWRRLFRRFDRDRSGSIDFNELQNALSSFGY--------RLSPQFVQLLvrkf 112

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*....
gi 76056882 278 ----GGHVDFDDFVELmgpkllaetadMIGVKELRDAFREFDTNGDGEI 322
Cdd:cd16180 113 drrrRGSISFDDFVEA-----------CVTLKRLTDAFRKYDTNRTGYA 150

calmodulin; Provisional

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 76056882  304 VKELRDAFREFDTNGDGEISTSELREAMRKLlGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMMSR 370
Cdd:PTZ00184  10 IAEFKEAFSLFDKDGDGTITTKELGTVMRSL-GQNPTEAELQDMINEVDADGNGTIDFPEFLTLMAR 75

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        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 230 LREAFREFDKDKDGYINCRDLGNCMRTMGYMPTEMELIELSQQINMNLGGHVDFDDFVELMgpKLLAETadmigvKELRD 309
Cdd:cd15898   2 LRRQWIKADKDGDGKLSLKEIKKLLKRLNIRVSEKELKKLFKEVDTNGDGTLTFDEFEELY--KSLTER------PELEP 73

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 76056882 310 AFREFDTNGDGEISTSELREAMRKLLGHQVGHRDIEEIIRDVDLNGDGR-VDFEEFVRMMS 369
Cdd:cd15898  74 IFKKYAGTNRDYMTLEEFIRFLREEQGENVSEEECEELIEKYEPERENRqLSFEGFTNFLL 134

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 76056882 232 EAFREFDKDKDGYINCRDLGNCMRTM-----GYMPTEMELIELSQQI----NMNLGGHVDFDDFVELMGP-----KLLAE 297
Cdd:cd15902   3 EVWMHFDADGNGYIEGKELDSFLRELlkalnGKDKTDDEVAEKKKEFmekyDENEDGKIEIRELANILPTeenflLLFRR 82

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 76056882 298 TADMIGVKELRDAFREFDTNGDGEISTSELREAMRKLLGHQVGHRD-------IEEIIRDVDLNGDGRVDFEEFVRMM 368
Cdd:cd15902  83 EQPLISSVEFMKIWRKYDTDGSGFIEAKELKGFLKDLLLKNKKHVSppkldeyTKLILKEFDANKDGKLELDEMAKLL 160

EF-hand domain pair;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 76056882   227 IEELREAFREFDKDKDGYINCRDLGNCMRTMGYM--PTEMELIELSQQINMNLGGHVDFDDFVELM 290
Cdd:pfam13499   1 EEKLKEAFKLLDSDGDGYLDVEELKKLLRKLEEGepLSDEEVEELFKEFDLDKDGRISFEEFLELY 66

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 76056882 235 REFDK--DKDGYINCRDLGN----CMRTMGYMPTEMELIELSQQINM---NLGGHVDFDDFVELMgpkllaetadmIGVK 305
Cdd:cd16182   4 ELFEKlaGEDEEIDAVELQKllnaSLLKDMPKFDGFSLETCRSLIALmdtNGSGRLDLEEFKTLW-----------SDLK 72

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 76056882 306 ELRDAFREFDTNGDGEISTSELREAMRKlLGHQVGHRDIEEII-RDVDlnGDGRVDFEEFVRMMSR 370
Cdd:cd16182  73 KWQAIFKKFDTDRSGTLSSYELRKALES-AGFHLSNKVLQALVlRYAD--STGRITFEDFVSCLVR 135

Ca2+-binding protein, EF-hand superfamily [Signal transduction mechanisms];

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 279 GHVDFDDFVELMGPkllaetadmigvkELRDAFREFDTNGDGEISTSELREAMRKLLGhQVGHRDIEEIIRDVDLNGDGR 358
Cdd:COG5126  20 GVLERDDFEALFRR-------------LWATLFSEADTDGDGRISREEFVAGMESLFE-ATVEPFARAAFDLLDTDGDGK 85

                        90
                ....*....|.
gi 76056882 359 VDFEEFVRMMS 369
Cdd:COG5126  86 ISADEFRRLLT 96

EF hand; The EF-hands can be divided into two classes: signalling proteins and buffering/transport proteins. The first group is the largest and includes the most well-known members of the family such as calmodulin, troponin C and S100B. These proteins typically undergo a calcium-dependent conformational change which opens a target binding site. The latter group is represented by calbindin D9k and do not undergo calcium dependent conformational changes.

                          10        20
                  ....*....|....*....|....*....
gi 76056882   306 ELRDAFREFDTNGDGEISTSELREAMRKL 334
Cdd:pfam00036   1 ELKEIFRLFDKDGDGKIDFEEFKELLKKL 29

EF-hand domain pair;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 76056882   318 GDGEISTSELREAMRKLLGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMMSR 370
Cdd:pfam13833   1 EKGVITREELKRALALLGLKDLSEDEVDILFREFDTDGDGYISFDEFCVLLER 53

The penta-EF hand (PEF) family; The penta-EF hand (PEF) family contains a group of five EF-hand calcium-binding proteins, including several classical calpain large catalytic subunits (CAPN1, 2, 3, 8, 9, 11, 12, 13, 14), two calpain small subunits (CAPNS1 and CAPNS2), as well as non-calpain PEF proteins, ALG-2 (apoptosis-linked gene 2, also termed programmed cell death protein 6, PDCD6), peflin, sorcin, and grancalcin. Based on the sequence similarity of EF1 hand, ALG-2 and peflin have been classified into group I PEF proteins. Calcium-dependent protease calpain subfamily members, sorcin and grancalcin, are group II PEF proteins. Calpains (EC 3.4.22.17) are calcium-activated intracellular cysteine proteases that play important roles in the degradation or functional modulation in a variety of substrates. They have been implicated in a number of physiological processes such as cell cycle progression, remodeling of cytoskeletal-cell membrane attachments, signal transduction, gene expression and apoptosis. ALG-2 is a pro-apoptotic factor that forms a homodimer in the cell or a heterodimer with its closest paralog peflin through their EF5s. Peflin is a 30-kD PEF protein with a longer N-terminal hydrophobic domain than any other member of the PEF family, and it contains nine nonapeptide (A/PPGGPYGGP) repeats. It exists only as a heterodimer with ALG-2. The dissociation of heterodimer occurs in the presence of Ca2+. ALG-2 interacts with various proteins in a Ca2+-dependent manner. Sorcin (for soluble resistance-related calcium binding protein) is a soluble resistance-related calcium-binding protein that participates in the regulation of calcium homeostasis in cells. Grancalcin is a cytosolic Ca2+-binding protein specifically expressed in neutrophils and monocytes/macrophages. It plays a key role in leukocyte-specific functions that are responsible for host defense. Grancalcin can form a heterodimer together with sorcin. Members in this family contain five EF-hand motifs attached to an N-terminal region of variable length containing one or more short Gly/Pro-rich sequences. These proteins form homodimers or heterodimers through pairing between the 5th EF-hands from the two molecules. Unlike calmodulin, the PEF domains do not undergo major conformational changes upon binding Ca2+.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 227 IEELREAFREFDKDKDGYINCRDLGNCMRTMGYMPTEmeliELSQQINMNLG---GHVDFDDFVELmgpkllaetadMIG 303
Cdd:cd15897  69 IKAWQEIFRTYDTDGSGTIDSNELRQALSGAGYRLSE----QTYDIIIRRYDrgrGNIDFDDFIQC-----------CVR 133

                        90
                ....*....|....*....
gi 76056882 304 VKELRDAFREFDTNGDGEI 322
Cdd:cd15897 134 LQRLTDAFRRYDKDQDGQI 152

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 76056882 199 SEADPFLhrlRPMLSSAFGQDrsLRPEEI-----EELREAFRE-FDKDKDGYINCRDLGNcmrtmgYMPTEMELIELSQQ 272
Cdd:cd16179  19 TELDGFL---REFVSSVNPED--VGPEVVsetalEELKEEFMEaYDENQDGRIDIRELAQ------LLPTEENFLLLFRR 87

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 273 INmnlgghvDFDDFVELMgpkllaetadmigvkelrDAFREFDTNGDGEISTSELREAMRKLLGHQVGHRDIEE------ 346
Cdd:cd16179  88 DN-------PLDSSVEFM------------------KVWREYDKDNSGYIEADELKNFLKHLLKEAKRDNDVSEdkliey 142

                       170       180
                ....*....|....*....|....*
gi 76056882 347 ---IIRDVDLNGDGRVDFEEFVRMM 368
Cdd:cd16179 143 tdtILQLFDRNKDGKLQLSEMARLL 167

EF-hand, calcium binding motif, found in homologs of mammalian apoptosis-linked gene 2 protein (ALG-2); The family includes some homologs of mammalian apoptosis-linked gene 2 protein (ALG-2) mainly found in lower eukaryotes, such as a parasitic protist Leishmarua major and a cellular slime mold Dictyostelium discoideum. These homologs contains five EF-hand motifs. Due to the presence of unfavorable residues at the Ca2+-coordinating positions, their non-canonical EF4 and EF5 hands may not bind Ca2+. Two Dictyostelium PEF proteins are the prototypes of this family. They may bind to cytoskeletal proteins and/or signal-transducing proteins localized to detergent-resistant membranes named lipid rafts, and occur as monomers or weak homo- or heterodimers like ALG-2. They can serve as a mediator for Ca2+ signaling-related Dictyostehum programmed cell death (PCD).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 229 ELREAFREFDKDKDGYINCRDLGNcMRTMGYMPTEMELIElsQQINM---NLGGHVDFDDFVELMgpKLLAEtadmigvk 305
Cdd:cd16185   1 ELRQWFRAVDRDRSGSIDVNELQK-ALAGGGLLFSLATAE--KLIRMfdrDGNGTIDFEEFAALH--QFLSN-------- 67

                        90       100       110       120       130       140
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 76056882 306 eLRDAFREFDTNGDGEISTSELREAMRKlLGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRM 367
Cdd:cd16185  68 -MQNGFEQRDTSRSGRLDANEVHEALAA-SGFQLDPPAFQALFRKFDPDRGGSLGFDDYIEL 127

EF-hand domain;

                          10        20
                  ....*....|....*....|....*....
gi 76056882   306 ELRDAFREFDTNGDGEISTSELREAMRKL 334
Cdd:pfam13405   1 ELREAFKLFDKDGDGKISLEELRKALRSL 29

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 76056882 204 FLHRLRPMlssafGQDRSLRPEEIEELREAFRE-FDKDKDGYINCRDLGNcmrtmgYMPTEMELIELSQQINMNLgghvd 282
Cdd:cd16178  25 FKDLLKKL-----GTKDTISADEVQDVKECFMSaYDVTGDGRIQIQELAN------IILPDDENFLLFFRREEPL----- 88

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 283 fDDFVELMgpkllaetadmigvkelrDAFREFDTNGDGEISTSELREAMRKLLgHQVGHRDIEE--------IIRDVDLN 354
Cdd:cd16178  89 -DSSVEFM------------------RIWRKYDADSSGYISAAELKNFLRDLF-LQHKKVITEDkldeytdtMMKIFDKN 148

                       170
                ....*....|....*
gi 76056882 355 GDGRVDFEEFVRMMS 369
Cdd:cd16178 149 KDGRLDLNDMARILA 163

Penta-EF hand, calcium binding motifs, found in sorcin, grancalcin, and similar proteins; The family corresponds to the second group of penta-EF hand (PEF) proteins that includes sorcin, grancalcin, and similar proteins. Sorcin, also termed 22 kDa Ca2+-binding protein, CP-22, or V19, is a soluble resistance-related calcium-binding protein that is expressed in normal mammalian tissues, such as the liver, lungs and heart. It contains a flexible glycine and proline-rich N-terminal extension and five EF-hand motifs that associate with membranes in a calcium-dependent manner. It may harbor three potential Ca2+ binding sites through its EF1, EF2 and EF3 hands. However, binding of only two Ca2+/monomer suffices to trigger the conformational change that exposes hydrophobic regions and leads to interaction with the respective targets. Sorcin forms homodimers through the association of the unpaired EF5 hand. Among the PEF proteins, sorcin is unique in that it contains potential phosphorylation sites by cAMP-dependent protein kinase (PKA), and it can form a tetramer at slightly acid pH values although remaining a stable dimer at neutral pH. Grancalcin (GCA) is a cytosolic Ca2+-binding protein specifically expressed in neutrophils and monocytes/macrophages. It can strongly interact with sorcin to form a heterodimer and further modulate the function of sorcin. GCA exists as homodimers in solution. It contains five EF-hand motifs attached to an N-terminal region of an approximately 50 residue-long segment rich in glycines and prolines. In contrast with sorcin, GCA binds two Ca2+ ions through its EF1 and EF3 hands.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 225 EEIEEL-------REAFREFDKDKDGYINCRDLGNCMRTMGYmptemeliELS-QQINM-----NLGGHVDFDDFVELmg 291
Cdd:cd16181  60 NEFKELwaalnqwKTTFMQYDRDRSGTVEPQELQQAIRSFGY--------NLSpQALNVivkrySKNGRITFDDFVAC-- 129

                        90       100
                ....*....|....*....|....*....
gi 76056882 292 pkllaetadMIGVKELRDAFREFDTNGDG 320
Cdd:cd16181 130 ---------AVRLRALTDRFRRRDTQQNG 149

EF-hand motif found in phosphoinositide phospholipase C delta (PI-PLC-delta); PI-PLC-delta isozymes represent a class of metazoan PI-PLCs that are some of the most sensitive to calcium among all PLCs. Their activation is modulated by intracellular calcium ion concentration, phospholipids, polyamines, and other proteins, such as RhoAGAP. Like other PI-PLC isozymes, PI-PLC-delta isozymes contain 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 C-terminal C2 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. There are three PI-PLC-delta isozymes (1, 3 and 4). PI-PLC-delta1 is relatively well characterized. It is activated by high calcium levels generated by other PI-PLC family members, and therefore functions as a calcium amplifier within the cell. Different PI-PLC-delta isozymes have different tissue distribution and different subcellular locations. PI-PLC-delta1 is mostly a cytoplasmic protein, PI-PLC-delta3 is located in the membrane, and PI-PLC-delta4 is predominantly detected in the cell nucleus. PI-PLC-delta isozymes is evolutionarily conserved even in non-mammalian species, such as yeast, slime molds and plants.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 76056882 307 LRDAFREFDTNGDGEISTSELREAMRKlLGHQVGHRDIEEIIRDVDLNGDGRVDFEEFV----RMMSR 370
Cdd:cd16202   2 LKDQFRKADKNGDGKLSFKECKKLLKK-LNVKVDKDYAKKLFQEADTSGEDVLDEEEFVqfynRLTKR 68

S-100: S-100 domain, which represents the largest family within the superfamily of proteins carrying the Ca-binding EF-hand motif. Note that this S-100 hierarchy contains only S-100 EF-hand domains, other EF-hands have been modeled separately. S100 proteins are expressed exclusively in vertebrates, and are implicated in intracellular and extracellular regulatory activities. Intracellularly, S100 proteins act as Ca-signaling or Ca-buffering proteins. The most unusual characteristic of certain S100 proteins is their occurrence in extracellular space, where they act in a cytokine-like manner through RAGE, the receptor for advanced glycation products. Structural data suggest that many S100 members exist within cells as homo- or heterodimers and even oligomers; oligomerization contributes to their functional diversification. Upon binding calcium, most S100 proteins change conformation to a more open structure exposing a hydrophobic cleft. This hydrophobic surface represents the interaction site of S100 proteins with their target proteins. There is experimental evidence showing that many S100 proteins have multiple binding partners with diverse mode of interaction with different targets. In addition to S100 proteins (such as S100A1,-3,-4,-6,-7,-10,-11,and -13), this group includes the ''fused'' gene family, a group of calcium binding S100-related proteins. The ''fused'' gene family includes multifunctional epidermal differentiation proteins - profilaggrin, trichohyalin, repetin, hornerin, and cornulin; functionally these proteins are associated with keratin intermediate filaments and partially crosslinked to the cell envelope. These ''fused'' gene proteins contain N-terminal sequence with two Ca-binding EF-hands motif, which may be associated with calcium signaling in epidermal cells and autoprocessing in a calcium-dependent manner. In contrast to S100 proteins, "fused" gene family proteins contain an extraordinary high number of almost perfect peptide repeats with regular array of polar and charged residues similar to many known cell envelope proteins.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 76056882 318 GDGE-ISTSELREAMRK----LLGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMM 368
Cdd:cd00213  22 GDKDtLSKKELKELLETelpnFLKNQKDPEAVDKIMKDLDVNKDGKVDFQEFLVLI 77

EF-hand motif found in phosphoinositide phospholipase C eta (PI-PLC-eta); PI-PLC-eta isozymes represent a class of neuron-specific metazoan PI-PLCs that are most abundant in the brain, particularly in the hippocampus, habenula, olfactory bulb, cerebellum, and throughout the cerebral cortex. They are phosphatidylinositol 4,5-bisphosphate-hydrolyzing enzymes that are more sensitive to Ca2+ than other PI-PLC isozymes. They function as calcium sensors activated by small increases in intracellular calcium concentrations. They are also activated through G-protein-coupled receptor (GPCR) stimulation, and further mediate GPCR signalling pathways. PI-PLC-eta isozymes contain an N-terminal pleckstrin homology (PH) domain, four atypical EF-hand motifs, a PLC catalytic core domain, a C2 domain, and a unique C-terminal tail that terminates with a PDZ-binding motif, a potential interaction site for other signaling proteins. The PLC catalytic core domain is a TIM barrel with two highly conserved regions (X and Y) split by a highly degenerate linker sequence. The C-terminal tail harbors a number of proline-rich motifs which may interact with SH3 (Src homology 3) domain-containing proteins, as well as many serine/threonine residues, suggesting possible regulation of interactions by protein kinases/phosphatases. There are two PI-PLC-eta isozymes (1-2). Aside from the PI-PLC-eta isozymes identified in mammals, their eukaryotic homologs are also present in this family.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 76056882 307 LRDAFREFDTNGDGEISTSELREAMRKLlghQVG--HRDIEEIIRDVDL-NGDGRVDFEEFV---RMMS 369
Cdd:cd16205   2 LKQTFEEADKNGDGLLSIGEILQLMHKL---NVNlpRRKVRQMFKEADTdDNQGTLDFEEFCafyKMMS 67

EF-hand, calcium binding motif, found in 45 kDa calcium-binding protein (Cab45); Cab45, also termed stromal cell-derived factor 4 (SDF-4), is a soluble, lumenal Golgi resident low-affinity Ca2+-binding protein that contains six copies of the EF-hand Ca2+-binding motif. It is required for secretory pathway calcium ATPase1 (SPCA1)-dependent Ca2+ import into the trans-Golgi network (TGN) and plays an essential role in Ca2+-dependent secretory cargo sorting at the TGN.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 297 ETADMIGVKELRDAFREFDTNGDGEISTSELRE-AMRKLLGH-QVGHRDIEEIIRDVDLNGDGRVDFEEF 364
Cdd:cd16225  26 EDSEPKKRKKLKEIFKKVDVNTDGFLSAEELEDwIMEKTQEHfQEAVEENEQIFKAVDTDKDGNVSWEEY 95

Eps15 homology domain; found in proteins implicated in endocytosis, vesicle transport, and signal transduction. The alignment contains a pair of EF-hand motifs, typically one of them is canonical and binds to Ca2+, while the other may not bind to Ca2+. A hydrophobic binding pocket is formed by residues from both EF-hand motifs. The EH domain binds to proteins containing NPF (class I), [WF]W or SWG (class II), or H[TS]F (class III) sequence motifs.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 76056882 309 DAFREFDTNGDGEISTSELREAMRK------LLGHqvghrdieeIIRDVDLNGDGRVDFEEFV 365
Cdd:cd00052   3 QIFRSLDPDGDGLISGDEARPFLGKsglprsVLAQ---------IWDLADTDKDGKLDKEEFA 56

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
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 76056882 311 FREFDTNGDGEISTSELREAMRKLlGHQVGHRDIEEIIRDVDLNGDGRVDFEEFVRMM 368
Cdd:cd16226  41 VDKIDKNGDGFVTEEELKDWIKYV-QKKYIREDVDRQWKEYDPNKDGKLSWEEYKKAT 97

N-terminal domain of Myosin essential light chain ELC; ELC is part of the apicomplexan membrane-associated protein complex called the glideosome, which is essential for parasite motility. The glideosome is composed of six proteins: myosin A (MyoA), essential light chain ELC, myosin light chain MLC1 (also called MTIP), and the glideosome-associated proteins GAP40, GAP45, and GAP50. MyoA is a Class XIV myosin implicated in gliding motility, as well as host cell and tissue invasion by parasites. ELC binds to the MyoA neck region adjacent to the MLC1-binding site, and both myosin light chains co-located to the glideosome. Although ELCs bind to a conserved MyoA sequence, P. falciparum ELC adopts a distinct structure in the free and MyoA-bound state. Therefore ELCs enhance MyoA performance by inducing alpha helical structure formation in MyoA and thus stiffening its lever arm. It has been shown that disruption of MyoA, MLC1, or ELC have dramatic effects on parasite motility but do not affect parasite shape or replication. The ELC N-terminal domain is part of the EF-hand calcium binding motif superfamily. Calcium binding has no effect on the structure of ELCs.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 228 EELREAFREFDKDKDGYINCRDLGNCMRTMGYMPTEMELIELSQQINMNlgghvDFDDFV 287
Cdd:cd22949   3 EKFREAFILFDRDGDGELTMYEAVLAMRSCGIPLTNDEKDALPASMNWD-----QFENWA 57

EF-hand, calcium binding motif, found in 45 kDa calcium-binding protein (Cab45); Cab45, also termed stromal cell-derived factor 4 (SDF-4), is a soluble, lumenal Golgi resident low-affinity Ca2+-binding protein that contains six copies of the EF-hand Ca2+-binding motif. It is required for secretory pathway calcium ATPase1 (SPCA1)-dependent Ca2+ import into the trans-Golgi network (TGN) and plays an essential role in Ca2+-dependent secretory cargo sorting at the TGN.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 224 PEEIEELREAFREFDKDKDGYINcrdlgncmrtmgymptemeLIELSQQINMNLGGHvdFDDFVElmgpkllaetadmig 303
Cdd:cd16225  30 PKKRKKLKEIFKKVDVNTDGFLS-------------------AEELEDWIMEKTQEH--FQEAVE--------------- 73

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 304 vkELRDAFREFDTNGDGEISTSELR--------------EAMRKLLGHQVGHRDIEE-IIRDV------DLNGDGRVDFE 362
Cdd:cd16225  74 --ENEQIFKAVDTDKDGNVSWEEYRvhfllskgyseeeaEEKIKNNEELKLDEDDKEvLDRYKdrwsqaDEPEDGLLDVE 151

                ..
gi 76056882 363 EF 364
Cdd:cd16225 152 EF 153

EF hand;

                          10        20
                  ....*....|....*....|....*
gi 76056882   344 IEEIIRDVDLNGDGRVDFEEFVRMM 368
Cdd:pfam13202   1 LKDTFRQIDLNGDGKISKEELRRLL 25

S-100A10_like: S-100A10 domain found in proteins similar to S100A10. S100A10 is a member of the S100 family of EF-hand superfamily of calcium-binding proteins. Note that the S-100 hierarchy, to which this S-100A1_like group belongs, contains only S-100 EF-hand domains, other EF-hands have been modeled separately. S100 proteins are expressed exclusively in vertebrates, and are implicated in intracellular and extracellular regulatory activities. A unique feature of S100A10 is that it contains mutation in both of the calcium binding sites, making it calcium insensitive. S100A10 has been detected in brain, heart, gastrointestinal tract, kidney, liver, lung, spleen, testes, epidermis, aorta, and thymus. Structural data supports the homo- and hetero-dimeric as well as hetero-tetrameric nature of the protein. S100A10 has multiple binding partners in its calcium free state and is therefore involved in many diverse biological functions.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|
gi 76056882 320 GEISTSELREAMRK----LLGHQVGHRDIEEIIRDVDLNGDGRVDFEEFV 365
Cdd:cd05031  25 NTLSRKELKKLMEKelseFLKNQKDPMAVDKIMKDLDQNRDGKVNFEEFV 74

Penta-EF hand, calcium binding motifs, found in Drosophila melanogaster calpain-A (CalpA), calpain-B (CalpB), and similar proteins; The family contains two calpains that have been found in Drosophila, CalpA and CalpB. CalpA, also termed calcium-activated neutral proteinase A (CANP A), or calpain-A catalytic subunit, is a Drosophila calpain homolog specifically expressed in a few neurons in the central nervous system, in scattered endocrine cells in the midgut, and in blood cells. CalpB, also termed calcium-activated neutral proteinase B (CANP B), contains calpain-B catalytic subunit 1 and calpain-B catalytic subunit 2. Both CalpA and CalpB are closely related to that of vertebrate calpains, and they share similar domain architecture, which consists of four domains: the N-terminal domain I, the catalytic domain II carrying the three active site residues, Cys, His and Asn, the Ca2+-regulated phospholipid-binding domain III, and penta-EF-hand Ca2+-binding domain IV. Besides, CalpA and CalpB display some distinguishing structural features that are not found in mammalian typical calpains. CalpA harbors a 76 amino acid long hydrophobic stretch inserted in domain IV, which may be involved in membrane attachment of this enzyme. CalpB has an unusually long N-terminal tail of 224 amino acids, which belongs to the class of intrinsically unstructured proteins (IUP) and may become ordered upon binding to target protein(s). Moreover, they do not need small regulatory subunits for their catalytic activity, and their proteolytic function is not regulated by an intrinsic inhibitor as the Drosophila genome contains neither regulatory subunit nor calpastatin orthologs. As a result, they may exist as a monomer or perhaps as a homo- or heterodimer together with a second large subunit. Furthermore, both CalpA and CalpB are dispensable for viability and fertility and do not share vital functions during Drosophila development. Phosphatidylinositol 4,5-diphosphate, phosphatidylinositol 4-monophosphate, phosphatidylinositol, and phosphatidic acid can stimulate the activity and the rate of activation of CalpA, but not CalpB. Calpain A modulates Toll responses by limited Cactus/IkappaB proteolysis. CalpB directly interacts with talin, an important component of the focal adhesion complex, and functions as an important modulator in border cell migration within egg chambers, which may act via the digestion of talin. CalpB can be phosphorylated by cAMP-dependent protein kinase (protein kinase A, PKA; EC 2.7.11.11) at Ser240 and Ser845, as well as by mitogen-activated protein kinase (ERK1 and ERK2; EC 2.7.11.24) at Thr747. The activation of the ERK pathway by extracellular signals results in the phosphorylation and activation of calpain B. In Schneider cells (S2), calpain B was mainly in the cytoplasm and upon a rise in Ca2+ the enzyme adhered to intracellular membranes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 218 QDRS--LRPEEIEEL-------REAFREFDKDKDGYINCRDLGNCMRTMGYMPTEMELIELSQQINmNLGGHVDFDDFVE 288
Cdd:cd16196  52 VDRSgkLGFEEFKKLwedlrswKRVFKLFDTDGSGSFSSFELRNALNSAGFRLSNATLNALVLRYS-NKDGRISFDDFIM 130

                        90       100       110
                ....*....|....*....|....*....|..
gi 76056882 289 LmgpkllaetadMIGVKELRDAFREFDTNGDG 320
Cdd:cd16196 131 C-----------AVKLKTMFEIFKEKDPRGGG 151

EF-hand, calcium binding motif, found in calbindin (CB); CB, also termed calbindin D28, or D-28K, or avian-type vitamin D-dependent calcium-binding protein, is a unique intracellular calcium binding protein that functions as both a calcium sensor and buffer in eukaryotic cells, which undergoes a conformational change upon calcium binding and protects cells against insults of high intracellular calcium concentration. CB is highly expressed in brain and sensory neurons. It plays essential roles in neural functioning, altering synaptic interactions in the hippocampus, modulating calcium channel activity, calcium transients, and intrinsic neuronal firing activity. It prevents a neuronal death, as well as maintains and controls calcium homeostasis. CB also modulates the activity of proteins participating in the development of neurodegenerative disorders such as Alzheimer's disease, Huntington's disease, and bipolar disorder. Moreover, CB interacts with Ran-binding protein M, a protein known to involve in microtubule function. It also interacts with alkaline phosphatase and myo-inositol monophosphatase, as well as caspase 3, an enzyme that plays an important role in the regulation of apoptosis. CB contains six EF-hand motifs in a single globular domain, where EF-hands 1, 3, 4, 5 bind four calcium ions with high affinity.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 76056882 232 EAFREFDKDKDGYINCRDLGNCMRTM--GYMPTEMELIE----LSQQINMNLGGHVDFDDFVELMGPK---LLAETADMI 302
Cdd:cd16176   3 EIWHHYDNDGNGYIEGKELQSFIQELqqARKKAGLELSDqmkaFVDQYGQSTDGKIGIVELAQILPTEenfLLFFRQQLK 82

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 76056882 303 GVKELRDAFREFDTNGDGEISTSELREAMRKLLghQVGHRDIEE---------IIRDVDLNGDGRVDFEEFVRMM 368
Cdd:cd16176  83 SSEEFMQTWRKYDADHSGFIEADELKSFLKDLL--KKANKPFDEskleeythtMLKMFDSNNDGKLGLTEMARLL 155