FIG 1.

Phospholipid biosynthesis pathways in E. coli. Chemical transformations for CL biosynthesis in E. coli cells. Abbreviations for phospholipids are the following: PA, phosphatidic acid; CDP-DAG, CDP diacylglycerol; PS, phosphatidylserine; PE, phosphatidylethanolamine; PG, phosphatidylglycerol; and CL, cardiolipin. The lipid composition of wild-type E. coli growing exponentially in typical laboratory growth conditions (37°C in rich medium with agitation) is 70% PE, 15% to 25% PG, and 5% to 10% CL.