Table 1 Classification of EF-hand Proteins

CTER (calmodulin, troponin C, essential and regulatory light chain) subfamily

calmodulin, troponin C, essential light chain of myosin, regulatory light chain of myosin

Others: Ca²⁺/CaM protein kinase, calsenilin, DREAM, calcineurin B like (CBL) sensors

CRP (calcineurin B, p22, recoverin) subfamily

calcineurin B, p22, recoverin (and other neuronal calcium sensor family)

Others: Ca²⁺/CaM protein kinase, calsenilin, DREAM, calcineurin B like (CBL) sensors

S100 subfamily

S100, calbindin D_9k, P26olf (dicalcin)

Fused gene family: profilaggrin, trichohyalin, repetin, hornerin, profilaggrin-related protein, cornulin

Other EF-hand subfamilies showing no strong congruence to one another

PENTA-EF-hand subfamily

Group II (calpain, calcium-dependent proteases, sorcin, grancalcin), Group I (ALG-2, peflin)

Proteins with six EF-hands

calbindin D28k, calretinin, Eps15 homology domain, CREC family (Ca²⁺-binding protein of 45 kDa, reticulocalbin, ER Ca²⁺-binding protein of 55 kDa, and calumenin), Plasmodium falciparum surface protein, calsymin

Proteins with eight and 12 EF-hands

Lytechinus pictus SPEC-resembling protein, EF12

Proteins with four EF-hands

Tetrahymena pyriformis calcium binding protein TCBP-25, TCBP-23, CBP, calcyphosine, Strongyrocentrotus purpuratus Ectoderm calcium binding protein SPEC, calflagin, sarcoplasm calcium binding protein, Hra32, EFH5, calcium vector protein, PM129 clone from Arabidopsis thaliana, calcium and integrin binding protein, spasmin, aequorin, Plasmodium falciparum protein kinase (PFCPK), protein phosphatase encoded by rdgC, phospholipase C, LAV1

Proteins with two-EF-hands

Phl p 7 (polcalcin), alpha-actinin, alpha-spectrin, calmodulin-related gene product encoded by T+, calsensin, groovin, diacylglycerol kinase, glycerol-3-phosphate dehydrogenase, fimbrin, ras guanyl nucleotide-releasing protein (GRP), polycystin-2, ryanodine receptor protein (RYR), CBL, nucleobindin, allograft inflammatory factor-1, BM-40 (osteonectin)

EF-hand proteins in bacteria and viruses

calerythrin, other EF-hand proteins in bacteria, MSV from pox virus