A novel prokaryotic trans-2-enoyl-CoA reductase from the spirochete Treponema denticola

An NADH-dependent trans-2-enoyl-CoA reductase (EC1.1.1.36) from the Gram negative spirochete Treponema denticola was identified, expressed and biochemically characterized. The recombinant protein is a monomeric enzyme with a molecular mass of 44 kDa with a specific activity of 43 ± 4.8 U/mg (μmol mg−1 min−1) and Km value of 2.7 μM for crotonoyl-CoA. This NADH-dependent trans-2-enoyl-CoA reductase represents the first enzymatically characterized member of a prokaryotic protein family involved in a fatty acid synthesis pathway that is distinct from the familiar fatty acid synthase system.