Protein EnvM is the NADH-dependent enoyl-ACP reductase (FabI) of Escherichia coli

The EnvM protein was purified from an overproducing Escherichia coli strain. It showed NADH-dependent enoyl-acyl carrier protein (ACP) reductase activity using both crotonyl-ACP and crotonyl-CoA as substrates. The protein bound a radioactive diazaborine derivative in the presence of NAD+ and radioactive NAD+ in the presence of the drug. Based on these data, it is concluded that EnvM is the NADH-dependent enoyl-ACP reductase (EC 1.3.1.9) of E. coli and we propose to rename the corresponding gene fabI.