An enoate reductase Achr-OYE4 from Achromobacter sp. JA81: characterization and application in asymmetric bioreduction of C=C bonds.

A putative enoate reductase, Achr-OYE4, was mined from the genome of Achromobacter sp. JA81, expressed in Escherichia coli, and was characterized. Sequence analysis and spectral properties indicated that Achr-OYE4 is a typical flavin mononucleotide-dependent protein; it preferred NADH over NADPH as a cofactor. The heterologously expressed protein displayed good activity and excellent stereoselectivity toward some activated alkenes in the presence of NADH, NADPH, or their recycling systems. The glucose dehydrogenase-based recycling system yielded the best results in most cases, with a product yield of up to 99 % and enantiopurity of >99 % ee. Achr-OYE4 is an important addition to the asymmetric reduction reservoir as an "old yellow enzyme" from Achromobacter.