Catalytic domain, repeat 2, of CDP-alcohol phosphatidyltransferase class-II family members
Catalytic domain, repeat 2, of CDP-alcohol phosphatidyltransferase class-II family members, which mainly include gram-negative bacterial phosphatidylserine synthases (PSS; CDP-diacylglycerol--serine O-phosphatidyltransferase, EC 2.7.8.8), yeast phosphatidylglycerophosphate synthase (PGP synthase; CDP-diacylglycerol--glycerol-3-phosphate 3-phosphatidyltransferase, EC 2.7.8.5), and metazoan PGP synthase 1. All members in this subfamily have two HKD motifs (H-x-K-x(4)-D, where x represents any amino acid residue) that characterize the phospholipase D (PLD) superfamily. They may utilize a common two-step ping-pong catalytic mechanism, involving a substrate-enzyme intermediate, to cleave phosphodiester bonds. The two motifs are suggested to constitute the active site involving phosphatidyl group transfer. Phosphatidylserine synthases from gram-positive bacteria and eukaryotes, and prokaryotic phosphatidylglycerophosphate synthases are not members of this subfamily.
Jiyao W et al.(2023). "The conserved domain database in 2023.",