Fig. 1

FA synthesis in E. coli vs Se7942 (a). Main FA synthesis pathway. In the initiation step, acetyl-CoA is converted into malonyl-CoA by the acetyl-CoA–carboxylase complex (AccABCD). Malonyl-CoA is transferred to the acyl-carrier protein (ACP) by FabD. Malonyl-CoA is condensed with acetyl-CoA by the β-ketoacyl-ACP synthase III (FabH). The resulting β-ketoacyl-ACP enters the elongation cycle, leading to long-chain acyl-ACP by serial steps of reduction (catalyzed by FabG), dehydration (FabZ and FabA), reduction (FabI), and elongation by condensing additional malonyl-ACP molecules (FabB and FabF). Enzymes present in E. coli and absent in Se7942 are colored in red. b Scheme of fab pathway gene organization in E. coli (upper panel) and Se7942 (lower panel). Homologous genes (or predicted ORFs) are depicted by arrows in the same color. The white arrow represents a gene not included in the fab cluster. Double slashes represent DNA regions that are not shown