Fold: EF Hand-like

core: 4 helices; array of 2 hairpins, opened

Lineage:

1. Root: scop
2. Class: All alpha proteins
3. Fold: EF Hand-like
   core: 4 helices; array of 2 hairpins, opened

Superfamilies:

1. EF-hand (7)
   Duplication: consists of two EF-hand units: each is made of two helices connected with calcium-binding loop
   1. Calbindin D9K (2)
      made of two EF-hands only
   2. S100 proteins (9)
      dimer: subunits are made of two EF-hands
   3. Osteonectin (1)
      5 helices; two EF-hands plus one of additional helices in the N-terminal part
   4. Parvalbumin (7)
      6-helices; array of 3 hairpins, closed
      made with two-helical hairpin and two EF-hands
   5. Calmodulin-like (27)
      Duplication: made with two pairs of EF-hands
   6. Eps15 homology domain (EH domain) (2)
   7. EF-hand modules in multidomain proteins (10)
2. Insect pheromon/odorant-binding proteins (1)
   the N-terminal extention, containing a few short helices, forms a flexible lid for the binding cavity
   1. Insect pheromon/odorant-binding proteins (2)
3. Cloroperoxidase (1)
   duplication: consists of 2 similar domains composed of 2 EF hand-like motifs each
   1. Cloroperoxidase (1)