This family consists of Lysophospholipase / phospholipase B EC:3.1.1.5 and cytosolic phospholipase A2 EC:3.1.4 which also has a C2 domain Pfam:PF00168. Phospholipase B enzymes catalyse the release of fatty acids from lysophsopholipids and are capable in vitro of hydrolysing all phospholipids extractable form yeast cells [1]. Cytosolic phospholipase A2 associates with natural membranes in response to physiological increases in Ca2+ and selectively hydrolyses arachidonyl phospholipids [2], the aligned region corresponds the the carboxy-terminal Ca2+-independent catalytic domain of the protein as discussed in [2].

1: Delineation of two functionally distinct domains of cytosolic phospholipase A2, a regulatory Ca(2+)-dependent lipid-binding domain and a Ca(2+)-independent catalytic domain. Nalefski EA, Sultzman LA, Martin DM, Kriz RW, Towler PS, Knopf JL, Clark JD; J Biol Chem 1994;269:18239-18249. PMID:8027085

2: The Saccharomyces cerevisiae PLB1 gene encodes a protein required for lysophospholipase and phospholipase B activity. Lee KS, Patton JL, Fido M, Hines LK, Kohlwein SD, Paltauf F, Henry SA, Levin DE; J Biol Chem 1994;269:19725-19730. PMID:8051052