Fig. 2.

Ribbon diagram of cPLA₂α structure. Two ions of calcium bind to the calcium-binding loops (CBL) on the membrane binding face of the C2 domain. The catalytic domain with the active site nucleophile S228 contains residues involved in cPLA₂α regulation (pink) that include phosphorylation sites (S505, S727), basic residues (K488, K544, K543), and W464 important for membrane interaction. The residues mutated in humans with cPLA₂α deficiencies are shown in yellow. The residue V707 is predicted to be the start of the deletion in patients with cryptogenic multifocal ulcerating stenosing enteritis.