2z7b
From Proteopedia
Crystal Structure of Mesorhizobium loti 3-hydroxy-2-methylpyridine-4,5-dicarboxylate decarboxylase
Overview
The function of the mlr6791 gene from Mesorhizobium loti MAFF303099 has been identified. This gene encodes 3-hydroxy-2-methylpyridine-4,5-dicarboxylate decarboxylase (HMPDdc), an enzyme involved in the catabolism of pyridoxal 5'-phosphate (Vitamin B6). This enzyme was overexpressed in Escherichia coli and characterized. HMPDdc is a 26 kDa protein that catalyzes the decarboxylation of 3-hydroxy-2-methylpyridine-4,5-dicarboxylate to 3-hydroxy-2-methylpyridine-5-carboxylate. The KM and kcat were found to be 366 microM and 0.6 s-1, respectively. The structure of this enzyme was determined at 1.9 A resolution using SAD phasing and belongs to the class II aldolase/adducin superfamily. While the decarboxylation of hydroxy-substituted benzene rings is a common motif in biosynthesis, the mechanism of this reaction is still poorly characterized. The structural studies described here suggest that catalysis of such decarboxylations proceeds by an aldolase-like mechanism.
About this Structure
2Z7B is a Single protein structure of sequence from Mesorhizobium loti. Full crystallographic information is available from OCA.
Reference
Gene identification and structural characterization of the pyridoxal 5'-phosphate degradative protein 3-hydroxy-2-methylpyridine-4,5-dicarboxylate decarboxylase from mesorhizobium loti MAFF303099., Mukherjee T, McCulloch KM, Ealick SE, Begley TP, Biochemistry. 2007 Nov 27;46(47):13606-15. Epub 2007 Oct 31. PMID:17973403 Page seeded by OCA on Sun May 4 20:01:26 2008
