S. aureus cls1 and cls2 induce accumulation of CL in CL-deficient E. coli (SD9). S. aureus cls1 and cls2 were cloned into the pRB474 vector and expressed in CL-deficient E. coli SD9. After overnight incubation, the bacteria were harvested, and lipids were extracted and analyzed as described in Materials and Methods. The migration of PE (phosphatidylethanolamine), PG, and CL in the strains tested, as determined by comigration of purified standards (only CL is shown), is indicated by arrows. The results shown are representative of three independent experiments.