calmodulin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  14 DEIKRLGKRFKKLDLDNSGSLSVEEF-MSLPELQQNPL---VQRVIDIFDTDGNGEVDFKEFIEGVSQFSVKGDKEQKLR 89
Cdd:PTZ00184   8 EQIAEFKEAFSLFDKDGDGTITTKELgTVMRSLGQNPTeaeLQDMINEVDADGNGTIDFPEFLTLMARKMKDTDSEEEIK 87

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528469158  90 FAFRIYDMDKDGYISNGELFQVLKMMvGNNLKDTQlqqiVDKTIINADKDGDGRISFEEFC 150
Cdd:PTZ00184  88 EAFKVFDRDGNGFISAAELRHVMTNL-GEKLTDEE----VDEMIREADVDGDGQINYEEFV 143

EF-hand domain pair;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158   85 EQKLRFAFRIYDMDKDGYISNGELFQVLKM-MVGNNLKDTQLQQIVDKtiinADKDGDGRISFEEFCAVV 153
Cdd:pfam13499   1 EEKLKEAFKLLDSDGDGYLDVEELKKLLRKlEEGEPLSDEEVEELFKE----FDLDKDGRISFEEFLELY 66

Eps15 homology domain; Pair of EF hand motifs that recognise proteins containing Asn-Pro-Phe (NPF) sequences.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 528469158    85 EQKLRFA--FRIYDMDKDGYISNGelfQVLKMMVGNNLKDTQLQQIVDKtiinADKDGDGRISFEEFCA 151
Cdd:smart00027   7 EDKAKYEqiFRSLDKNQDGTVTGA---QAKPILLKSGLPQTLLAKIWNL----ADIDNDGELDKDEFAL 68

calmodulin; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  14 DEIKRLGKRFKKLDLDNSGSLSVEEF-MSLPELQQNPL---VQRVIDIFDTDGNGEVDFKEFIEGVSQFSVKGDKEQKLR 89
Cdd:PTZ00184   8 EQIAEFKEAFSLFDKDGDGTITTKELgTVMRSLGQNPTeaeLQDMINEVDADGNGTIDFPEFLTLMARKMKDTDSEEEIK 87

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528469158  90 FAFRIYDMDKDGYISNGELFQVLKMMvGNNLKDTQlqqiVDKTIINADKDGDGRISFEEFC 150
Cdd:PTZ00184  88 EAFKVFDRDGNGFISAAELRHVMTNL-GEKLTDEE----VDEMIREADVDGDGQINYEEFV 143

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 528469158  87 KLRFAFRIYDMDKDGYISNGELFQVLKMmvgnnLKDTQLQQIVDKTIINADKDGDGRISFEEFCAVV 153
Cdd:cd00051    1 ELREAFRLFDKDGDGTISADELKAALKS-----LGEGLSEEEIDEMIREVDKDGDGKIDFEEFLELM 62

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 528469158   8 EKLVDADEikrlgKRFKKLDLDNSGSLSVEEFMSLpelqQNP---------LVQRVIDIFDTDGNGEVDFKEFI-EGVSQ 77
Cdd:cd16227  118 LKLLEDDK-----EMFEAADLNKDGKLDKTEFSAF----QHPeeyphmhpvLIEQTLRDKDKDNDGFISFQEFLgDRAGH 188

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 528469158  78 FSVKGDKEQKLRFAfRIYDMDKDGYISNGElfqVLKMMVGNNlkDTQLQQIVDKTIINADKDGDGRISFEE 148
Cdd:cd16227  189 EDKEWLLVEKDRFD-EDYDKDGDGKLDGEE---ILSWLVPDN--EEIAEEEVDHLFASADDDHDDRLSFDE 253

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 528469158  23 FKKLDLDNSGSLSVeefmslPELQQ-----NPL-----VQRVIDIFDTDGNGEVDFKEFiEGVSQFSvkgdkeQKLRFAF 92
Cdd:cd16185    6 FRAVDRDRSGSIDV------NELQKalaggGLLfslatAEKLIRMFDRDGNGTIDFEEF-AALHQFL------SNMQNGF 72

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 528469158  93 RIYDMDKDGYISNGELFQVLKmMVGNNLKDTQLQQIVDKtiinADKDGDGRISFEEF 149
Cdd:cd16185   73 EQRDTSRSGRLDANEVHEALA-ASGFQLDPPAFQALFRK----FDPDRGGSLGFDDY 124

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

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  11 VDADEIKRLGKR-----FKKLDLDNSGSLSVEEFM----SLPELQQNPLVQRVIDIFDTDGNGEVDFKEFIEGvsqFSVK 81
Cdd:COG5126   22 LERDDFEALFRRlwatlFSEADTDGDGRISREEFVagmeSLFEATVEPFARAAFDLLDTDGDGKISADEFRRL---LTAL 98

                         90       100       110
                 ....*....|....*....|....*....|..
gi 528469158  82 GDKEQKLRFAFRIYDMDKDGYISNGELFQVLK 113
Cdd:COG5126   99 GVSEEEADELFARLDTDGDGKISFEEFVAAVR 130

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

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528469158   3 MTARQEKLVDADEIKRLGKRFKKLDLDNSGSLSVEEFMSLPELQQ--NPLVQRVIDIFDTDGNGEVDFKEFIEGVSQF 78
Cdd:COG5126   55 FVAGMESLFEATVEPFARAAFDLLDTDGDGKISADEFRRLLTALGvsEEEADELFARLDTDGDGKISFEEFVAAVRDY 132

EF-hand, calcium binding motif, found in peflin and similar proteins; Peflin, also termed penta-EF hand (PEF) protein with a long N-terminal hydrophobic domain, or penta-EF hand domain-containing protein 1, 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+. In lower vertebrates, peflin may interact with transient receptor potential N (TRPN1), suggesting a potential role of peflin in fast transducer channel adaptation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  23 FKKLDLDNSGSLSVEEfmslpeLQQnPLV------------QRVIDIFDTDGNGEVDFKEFiEGVSQFSvkgdkeQKLRF 90
Cdd:cd16184    6 FQAVDRDRSGKISAKE------LQQ-ALVngnwshfndetcRLMIGMFDKDKSGTIDIYEF-QALWNYI------QQWKQ 71

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 528469158  91 AFRIYDMDKDGYISNGELFQVLKMMvGNNLKDTQLQQIVDKtiinADKDGDGRISFEEF 149
Cdd:cd16184   72 VFQQFDRDRSGSIDENELHQALSQM-GYRLSPQFVQFLVSK----YDPRARRSLTLDQF 125

EF-hand, calcium binding motif, found in reticulocalbin-2 (RCN2); RCN2, also termed calcium-binding protein ERC-55, or E6-binding protein (E6BP), or TCBP-49, is an endoplasmic reticulum resident low-affinity Ca2+-binding protein that has been implicated in immunity, redox homeostasis, cell cycle regulation and coagulation. It is associated with tumorigenesis, in particular with transformation of cells of the cervix induced by human papillomavirus (HPV), through binding to human papillomavirus (HPV) E6 oncogenic protein. It specifically interacts with vitamin D receptor among nuclear receptors. RCN2 contains an N-terminal signal sequence followed by six copies of the EF-hand Ca2+-binding motif, and 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 528469158  21 KRFKKLDLDNSGSLSVEEFMSL--PE---LQQNPLVQRVIDIFDTDGNGEVDFKEFI------EGVSQfSVKGDKEQKLR 89
Cdd:cd16224  128 KRFDKANTDGGPGLNLTEFIAFehPEevdYMTEFVIQEALEEHDKDGDGFISLEEFLgdyrkdPTANE-DPEWIIVEKDR 206

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 528469158  90 FAfRIYDMDKDGYISNGELfqvLKMMVGNNLKDTQLQQIvdKTIINADKDGDGRISFEE 148
Cdd:cd16224  207 FV-NDYDKDNDGKLDPQEL---LPWVVPNNYGIAQEEAL--HLIDEMDLNGDGRLSEEE 259

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 528469158  23 FKKLDLDNSGSLSVEEfmslpeLQQ----------NPLVQR-VIDIFDTDGNGEVDFKEFiEGVSQFSvkgdkeQKLRFA 91
Cdd:cd16183    6 FQRVDKDRSGQISATE------LQQalsngtwtpfNPETVRlMIGMFDRDNSGTINFQEF-AALWKYI------TDWQNC 72

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528469158  92 FRIYDMDKDGYISNGELFQVLKMMvGNNLKDTQLQQIVDKTiinaDKDGDGRISFEEF--CAVV 153
Cdd:cd16183   73 FRSFDRDNSGNIDKNELKQALTSF-GYRLSDQFYDILVRKF----DRQGRGTIAFDDFiqCCVV 131

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 528469158  64 GEVDFKEFIEGVSqfsVKGDKEQKLRFAFRIYDMDKDGYISNGELFQVLKMM--VGNNLKDTQLQQIvdktIINADKDGD 141
Cdd:cd16251   15 GSFNYKKFFEHVG---LKQKSEDQIKKVFQILDKDKSGFIEEEELKYILKGFsiAGRDLTDEETKAL----LAAGDTDGD 87

                         90
                 ....*....|....
gi 528469158 142 GRISFEEFCAVVGG 155
Cdd:cd16251   88 GKIGVEEFATLVAG 101

EF-hand, calcium binding motif, found in alpha-parvalbumin; Alpha-parvalbumin is cytosolic Ca2+/Mg2+-binding protein expressed mainly in fast-twitch skeletal myofibrils, where it may act as a soluble relaxing factor facilitating the Ca2+-mediated relaxation phase. It is also expressed in rapidly firing neurons, particularly GABA-ergic neurons, and thus may confer protection against Ca2+ toxicity. The major role of alpha-parvalbumin is metal buffering and transport of Ca2+. It binds different metal cations, and exhibits very high affinity for Ca2+ and physiologically significant affinity for Mg2+. Alpha-parvalbumin is 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+. Both metal ion-binding sites in alpha-parvalbumin are high-affinity sites. Additionally, in contrast to beta-parvalbumin, alpha-parvalbumin is less acidic and has an additional residue in the C-terminal helix.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  67 DFKEFIEGVSqfsVKGDKEQKLRFAFRIYDMDKDGYISNGELFQVLKMMV--GNNLKDTQLQQIVDKtiinADKDGDGRI 144
Cdd:cd16254   18 DYKKFFEMVG---LKKKSADDVKKVFHILDKDKSGFIEEDELKFVLKGFSpdGRDLSDKETKALLAA----GDKDGDGKI 90

                 ....*....
gi 528469158 145 SFEEFCAVV 153
Cdd:cd16254   91 GIDEFATLV 99

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 528469158  21 KRFKKLDLDNSGSLSVEE---FMSLPELQQNPLV---------QRVIDIFDTDGNGEVDFKEFIEGVS-------QFSVK 81
Cdd:cd15902   94 KIWRKYDTDGSGFIEAKElkgFLKDLLLKNKKHVsppkldeytKLILKEFDANKDGKLELDEMAKLLPvqenfllKFQIL 173

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 528469158  82 GDKEQK---LRFAFRIYDMDKDGYISNGELFQVLKMMVGNNLKDTQLQQIVD--KTIIN-ADKDGDGRISFEEFC 150
Cdd:cd15902  174 GAMDLTkedFEKVFEHYDKDNNGVIEGNELDALLKDLLEKNKADIDKPDLENfrDAILRaCDKNKDGKIQKTELA 248

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 528469158  12 DADEIKRLGKRFKKLDLDNSGSLSVEEFMSLPELQQNP-----LVQRVIDIFDTDGNGEVDFKEFIEG--------VSQF 78
Cdd:cd16225  126 DKEVLDRYKDRWSQADEPEDGLLDVEEFLSFRHPEHSRgmlknMVKEILHDLDQDGDEKLTLDEFVSLppgtveeqQAED 205

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  79 SVKGDKEQKLRFAFRIyDMDKDGYISNGELFQVLKMMvgnnlKDTQLQQIVDKTIINADKDGDGRISFEE 148
Cdd:cd16225  206 DDEWKKERKKEFEEVI-DLNHDGKVTKEELEEYMDPR-----NERHALNEAKQLIAVADENKDGKLSLEE 269

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 528469158  23 FKKLDLDNSGSLSVEEFMS-LPELQQN---PLVQRVIDIFDTDGNGEVDFKEFIEGVsqFSVKGdkeqkLRFAFRIYDMD 98
Cdd:cd16180   73 FRRFDRDRSGSIDFNELQNaLSSFGYRlspQFVQLLVRKFDRRRRGSISFDDFVEAC--VTLKR-----LTDAFRKYDTN 145

                 ....*
gi 528469158  99 KDGYI 103
Cdd:cd16180  146 RTGYA 150

centrin; Provisional

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 528469158  72 IEGVSQFSVKGDKEQKLRFAFRIYDMDKDGYISNGELFQVLKMMvGNNLKDTQLQQIvdktIINADKDGDGRISFEEF 149
Cdd:PTZ00183   3 KRRSERPGLTEDQKKEIREAFDLFDTDGSGTIDPKELKVAMRSL-GFEPKKEEIKQM----IADVDKDGSGKIDFEEF 75

EF-hand, calcium binding motif, found in reticulocalbin-3 (RCN-3); RCN-3, also termed EF-hand calcium-binding protein RLP49, 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 His-Asp-Glu-Leu (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 528469158   8 EKLVDADEIKRLGKRFKKLDL--DNSGSLSVEEFMSLPELQQN----PLVQRVIDIFDTDGNGEVDFKEF-------IEG 74
Cdd:cd16230   26 DQLSPEESQARLGRIVDRMDRagDGDGWVSLAELRAWIAHTQQrhirDSVSAAWQTYDTDRDGRVGWEELrnatyghYEP 105

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  75 VSQFSVKGDKEQKLRF------AFRIYDMDKDGYISNGELFQVLKMMVGNNLKDTqlqqIVDKTIINADKDGDGRISFEE 148
Cdd:cd16230  106 GEEFHDVEDAETYKKMlarderRFRVADQDGDSMATREELTAFLHPEEFPHMRDI----VVAETLEDLDKNKDGYVQVEE 181

                 ...
gi 528469158 149 FCA 151
Cdd:cd16230  182 YIA 184

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 528469158  17 KRLGKRFKKLDLDNSGSLSVEEFMSLPELQQNPL----VQRVIDIFDTDGNGEVDFKEFIegVSQFSVKGDKEQ------ 86
Cdd:cd15899   35 RRLGVIVSKMDVDKDGFISAKELHSWILESFKRHameeSKEQFRAVDPDEDGHVSWDEYK--NDTYGSVGDDEEnvadni 112

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 528469158  87 -----------KLRFAFRIYDMDKDGYISNGELFQVLKMMVGNNLKDTQLQQIVDktiiNADKDGDGRISFEEF 149
Cdd:cd15899  113 kedeeykklllKDKKRFEAADQDGDLILTLEEFLAFLHPEESPYMLDFVIKETLE----DLDKNGDGFISLEEF 182

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        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  23 FKKLDLDNSGSLSVEEFMSLPEL--QQNPLVQRVIDI------------------FDTDGNGEVDFKEFIEGVSQFSVKG 82
Cdd:cd15900    6 FKMFDLDGDGELDKEEFNKVQSIirSQTSVGQRHRDHtngestklgmnstlaryfFGKDGKQKLSIEKFLEFQENLQEEI 85

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528469158  83 DKeqkLRFAFRIYDMdKDGYISNGELFQVLKMMVGNNLKDtqlqQIVDKTIINADKDGDGRISFEEFCAV 152
Cdd:cd15900   86 DD---VDTALTFYHL-AGASIDRKTFKRAAKVVAGVELSD----HVVDVVFTIFDEDGDGILSHKEFISV 147

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 528469158  23 FKKLDLDnSGSLSVEEFMSL--------PELQQNPLVQR-VIDIFDTDGNGEVDFKEFiEGVSQFsVKGDKEqklrfAFR 93
Cdd:cd15897    6 FQAVAGD-DGEISATELQQAlsnvgwthFDLGFSLETCRsMIAMMDRDHSGKLNFSEF-KGLWNY-IKAWQE-----IFR 77

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 528469158  94 IYDMDKDGYISNGELFQVLKMMvGNNLKDTQLQQIVDKTiinadKDGDGRISFEEF 149
Cdd:cd15897   78 TYDTDGSGTIDSNELRQALSGA-GYRLSEQTYDIIIRRY-----DRGRGNIDFDDF 127

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 528469158  16 IKRLGKRFKKLDLDNSGSLSVEEF---MSLPELQQNP-LVQRVIDIFDtDGNGEVDFKEFIEGVSqfsvkgdKEQKLRFA 91
Cdd:cd15897   69 IKAWQEIFRTYDTDGSGTIDSNELrqaLSGAGYRLSEqTYDIIIRRYD-RGRGNIDFDDFIQCCV-------RLQRLTDA 140

                         90
                 ....*....|..
gi 528469158  92 FRIYDMDKDGYI 103
Cdd:cd15897  141 FRRYDKDQDGQI 152

Penta-EF hand, calcium binding motifs, found in calpain-9 (CAPN9); CAPN9, also termed digestive tract-specific calpain, or new calpain 4 (nCL-4), or protein CG36, is a calpain large subunit predominantly expressed in gastrointestinal tract. It plays a physiological role in the suppression of tumorigenesis. It acts as an important biomolecule link for the regression of colorectal cancer via intracellular calcium homeostasis. CAPN9 may also play a critical role in lumen formation. Moreover, CAPN9, together with CAPN8, forms an active protease complex, G-calpain, in which both proteins are essential for stability and activity. The G-Calpain has been implicated in gastric mucosal defense. Furthermore, down-regulation of calpain 9 has been linked to hypertensive heart and kidney disease in salt-sensitive Dahl rats. CAPN9 contains 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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 528469158  54 VIDIFDTDGNGEVDFKEfiegvsqFSVKGDKEQKLRFAFRIYDMDKDGYISNGELFQVLKmMVGNNLKDTQLQQIV 129
Cdd:cd16192   48 IISLMDTSGNGKLGFSE-------FKVFWDKLKKWIGLFLKYDADRSGTMSSYELRSALK-AAGFQLNNQLLQLIV 115

Cytoskeletal-regulatory complex EF hand; This is an efhand family from the N-terminal of actin cytoskeleton-regulatory complex END3 and similar proteins from fungi and closely related species.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 528469158   99 KDGYISNGELFQVLKmmvGNNLKDTQLQQIVDKtiinADKDGDGRISFEEFC 150
Cdd:pfam12763  22 ENNKLTGDQVSPVLK---NSRLPDDQLAKIWDL----ADIDSDGKLDFEEFC 66

EF-hand domain pair;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 528469158   99 KDGYISNGELFQVLKMMVGNNLKDTQLQQIVDKtiinADKDGDGRISFEEFCAVV 153
Cdd:pfam13833   1 EKGVITREELKRALALLGLKDLSEDEVDILFRE----FDTDGDGYISFDEFCVLL 51

EF-hand domain;

                          10        20
                  ....*....|....*....|....*....
gi 528469158   87 KLRFAFRIYDMDKDGYISNGELFQVLKMM 115
Cdd:pfam13405   1 ELREAFKLFDKDGDGKISLEELRKALRSL 29