Transcription factor involved in regulation of membrane lipid biosynthesis by repressing genes involved in fatty acid and phospholipid metabolism. Binds to the 5'-TTAGTANNNNNTANTAA-3' consensus sequence found in the promoter of fabHAF operon (containing fabHA and fabF genes), yhdO and fapR genes and prevents their expression. Its action is probably modulated by malonyl-CoA. Autoregulated. Belongs to the FapR family.