Fungal phospholipase B are Group IV cPLA2 homologs. Aspergillus PLA2 is Ca-dependent, yet it does not contain a C2 domain. PLB deacylates both sn-1 and sn-2 chains of phospholipids and are abundantly expressed in fungi. It shows lysophospholipase (lysoPL) and transacylase activities. The active site residues from cPLA2 are also conserved in PLB. Like cPLA2, PLB also has a consensus sequence of Sm-X-Nu-Sm (Sm = small residue, X = any residue and Nu = nucleophile). It includes PLB1 from Schizosaccharomyces pombe, PLB2 from Candida glabrata, and PLB3 from Saccharomyces cerevisiae. PLB1, PLB2, and PLB3 show PLB and lysoPL activities; PLB3 is specific for phosphoinositides.
Jiyao W et al.(2023). "The conserved domain database in 2023.",