This protein of fatty acid/phospholipid biosynthesis, called PlsX after the member in Streptococcus pneumoniae, is proposed to be a phosphate acyltransferase that partners with PlsY (TIGR00023) in a two-step 1-acylglycerol-3-phosphate biosynthesis pathway alternative to the one-step PlsB (EC 2.3.1.15) pathway. [Fatty acid and phospholipid metabolism, Biosynthesis]