Superfamily: EF-hand

Duplication: consists of two EF-hand units: each is made of two helices connected with calcium-binding loop

Lineage:

1. Root: scop
2. Class: All alpha proteins
3. Fold: EF Hand-like
   core: 4 helices; array of 2 hairpins, opened
4. Superfamily: EF-hand
   Duplication: consists of two EF-hand units: each is made of two helices connected with calcium-binding loop

Families:

1. Calbindin D9K (2)
   made of two EF-hands only
   1. Calbindin D9K
      1. Cow (Bos taurus) (12)
      2. Pig (Sus scrofa) (1)
2. S100 proteins (9)
   dimer: subunits are made of two EF-hands
   1. Calcyclin (S100)
      1. Rabbit (Oryctolagus cuniculus) (3)
      2. Rat (Rattus norvegicus), s100b (4)
      3. Cow (Bos taurus), s100b (2)
      4. Human (Homo sapiens), s100b (1)
      5. Human (Homo sapiens), P11 s100a10, calpactin (2)
         ligand of annexin II
      6. Human (Homo sapiens), psoriasin s100a7 (3)
      7. Pig (Sus scrofa), calgizzarin s100c (s100a11) (1)
      8. Human (Homo sapiens), calgranulin s100a8, MRP8 (1)
         Migration inhibitory factor-related protein 8
      9. Human (Homo sapiens), calgranulin C, s100a12 (1)
3. Osteonectin (1)
   5 helices; two EF-hands plus one of additional helices in the N-terminal part
   1. C-terminal (EC) domain of BM-40/SPARC/osteonectin
      1. Human (Homo sapiens) (3)
4. Parvalbumin (7)
   6-helices; array of 3 hairpins, closed
   made with two-helical hairpin and two EF-hands
   1. Oncomodulin
      1. Rat (Rattus norvegicus) (2)
   2. Parvalbumin
      1. Carp (Cyprinus carpio) (7)
      2. Pike (Esox lucius) (9)
      3. Leopard shark (Triakis semifasciata) (1)
      4. Whiting (Merlangius merlangus) (1)
      5. Silver hake (Merluccius bilinearis) (1)
      6. Rat (Rattus rattus) (1)
5. Calmodulin-like (27)
   Duplication: made with two pairs of EF-hands
   1. Troponin C
      1. Chicken (Gallus gallus) (21)
      2. Turkey (Meleagris gallopavo) (2)
      3. Rabbit (Oryctolagus cuniculus) (4)
      4. Chicken (Gallus gallus), cardiac isoform (1)
      5. Human (Homo sapiens), cardiac isoform (3)
   2. Sarcoplasmic calcium-binding protein
      1. Sandworm (Nereis diversicolor) (1)
      2. Amphioxus (Branchiostoma lanceolatum) (1)
   3. Aequorin
      structurally most similar to sarcoplasmic calcium-binding protein
      1. Jellyfish (Aequorea aequorea) (1)
   4. Calcium vector protein
      1. Amphioxus (Branchiostoma lanceolatum) (2)
   5. Calmodulin
      1. Human (Homo sapiens) (2)
      2. Cow (Bos taurus) (13)
      3. Rat (Rattus rattus) (1)
      4. Chicken (Gallus gallus) (1)
         mutant with a two residue deletion in the central helix
      5. African frog (Xenopus laevis) (8)
      6. Drosophila melanogaster (3)
      7. Ciliate (Paramecium tetraurelia) (3)
   6. Myosin Essential Chain
      1. Bay scallop (Aequipecten irradians) (5)
      2. Chicken (Gallus gallus) (3)
   7. Myosin Regulatory Chain
      1. Bay scallop (Aequipecten irradians) (5)
      2. Chicken (Gallus gallus) (1)
   8. Calcineurin regulatory subunit (B-chain)
      1. Cow (Bos taurus) (1)
      2. Human (Homo sapiens) (1)
   9. Recoverin
      Calcium-myristoyl switch; only one EF-hand is functional
      1. Cow (Bos taurus) (3)
   10. Frequenin
       1. Baker's yeast (Saccharomyces cerevisiae) (1)
   11. Guanylate cyclase activating protein 2, GCAP-2
       1. Cow (Bos taurus) (1)
   12. Neurocalcin
       1. Cow (Bos taurus) (1)
   13. Calium- and integrin-binding protein, CIB
       1. Human (Homo sapiens) (2)
6. Eps15 homology domain (EH domain) (2)
   1. Eps15
      1. Mouse (Mus musculus) (1)
      2. Human (Homo sapiens) (4)
7. EF-hand modules in multidomain proteins (10)
   1. Phosphoinositide-specific phospholipase C, isozyme D1 (PLC-D!)
      1. Rat (Rattus norvegicus) (10)
   2. Grancalcin
      Calpain small subunit homologue
      1. Human (Homo sapiens) (2)
   3. Calpain small (regulatory) subunit (domain VI)
      1. Human (Homo sapiens) (1)
      2. Rat (Rattus norvegicus) (3)
      3. Pig (Sus scrofa) (2)
   4. Calpain large subunit, C-terminal domain (domain IV)
      1. Human (Homo sapiens) (1)
      2. Rat (Rattus norvegicus) (1)
   5. Dystrophin
      probably lost calcium-binding function; contains extra helices in each domain
      1. Human (Homo sapiens) (2)
   6. Cbl
      1. Human (Homo sapiens) (3)
   7. alpha-Spectrin
      1. Chicken (Gallus gallus) (1)