A novel Fe(II)/α-ketoglutarate-dependent dioxygenase from Burkholderia ambifaria has β-hydroxylating activity of N-succinyl L-leucine

An Fe(II)/alpha-ketoglutarate-dependent dioxygenase, SadA, was obtained from Burkholderia ambifaria AMMD and heterologously expressed in Escherichia coli. Purified recombinant SadA had catalytic activity towards several N-substituted L-amino acids, which was especially strong with N-succinyl L-leucine. With the NMR and LC-MS analysis, SadA converted N-succinyl L-leucine into N-succinyl L-threo-beta-hydroxyleucine with >99% diastereoselectivity. SadA is the first enzyme catalysing beta-hydroxylation of aliphatic amino acid-related substances and a potent biocatalyst for the preparation of optically active beta-hydroxy amino acids.