 Only the PKC-C2 domain family contains conserved calcium-binding residues, suggesting the typical calcium-dependent membrane interaction is a derived feature limited in PKC-C2 domains.C2 domains are unique among membrane targeting domains in that they show wide range of lipid selectivity for the major components of cell membranes, including phosphatidylserine and phosphatidylcholine.This C2 domain is about 116 amino-acid residues and is located between the two copies of the C1 domain in Protein Kinase C (that bind phorbol esters and diacylglycerol) (see PDOC00379) and the protein kinase catalytic domain (see PDOC00100).