4om8

Publication Abstract from PubMed

5-Formyl-3-hydroxy-2-methylpyridine 4-carboxylic acid 5-dehydrogenase (FHMPCDH) from Mesorhizobium loti is the fifth enzyme in degradation pathway I for pyridoxine. The enzyme catalyzes a dismutation reaction: the oxidation of 5-formyl-3-hydroxy-2-methylpyridine 4-carboxylic acid (FHMPC) to 3-hydroxy-2-methylpyridine 4,5-dicarboxylic acid with NAD(+) and reduction of FHMPC to 4-pyridoxic acid with NADH. FHMPCDH belongs to the l-3-hydroxyacyl-CoA dehydrogenase (HAD) family. The crystal structure was determined by molecular replacement and refined to a resolution of 1.55A (R-factor of 16.4%, Rfree=19.4%). There were two monomers in the asymmetric unit. The overall structure of the monomer consisted of N- and C-terminal domains connected by a short linker loop. The monomer was similar to members of the HAD family (RMSD=1.9A). The active site was located between the domains and highly conserved to that of human heart l-3-hydroxyacyl-CoA dehydrogenase (HhHAD). His-Glu catalytic dyad, a serine and two asparagine residues of HhHAD were conserved. Ser116, His137 and Glu149 in FHMPCDH are connected by a hydrogen bonding network forming a catalytic triad. The functions of the active site residues in the reaction mechanism are discussed.

Crystal structure of 5-formyl-3-hydroxy-2-methylpyridine 4-carboxylic acid 5-dehydrogenase, an NAD(+)-dependent dismutase from Mesorhizobium loti.,Mugo AN, Kobayashi J, Mikami B, Yoshikane Y, Yagi T, Ohnishi K Biochem Biophys Res Commun. 2015 Jan 2;456(1):35-40. doi:, 10.1016/j.bbrc.2014.11.028. Epub 2014 Nov 18. PMID:25446130^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.