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 (micromol mg(-1)min(-1)) and K(m) value of 2.7 microM 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.