2Z7B

Crystal Structure of Mesorhizobium loti 3-hydroxy-2-methylpyridine-4,5-dicarboxylate decarboxylase

Summary for 2Z7B

• Entry DOI: 10.2210/pdb2z7b/pdb
• Descriptor: Mlr6791 protein, MANGANESE (II) ION (3 entities in total)
• Functional Keywords: class ii aldolase superfamily, lyase
• Biological source: Mesorhizobium loti
• Total number of polymer chains: 1
• Total formula weight: 30273.38

Authors

McCulloch, K.M.,Mukherjee, T.,Ealick, S.E.,Begley, T.P. (deposition date: 2007-08-17, release date: 2007-11-13, Last modification date: 2024-11-13)

Primary citation

Mukherjee, T.,McCulloch, K.M.,Ealick, S.E.,Begley, T.P.
Gene Identification and Structural Characterization of the Pyridoxal 5'-Phosphate Degradative Protein 3-Hydroxy-2-methylpyridine-4,5-dicarboxylate Decarboxylase from Mesorhizobium loti MAFF303099
Biochemistry, 46:13606-13615, 2007

PubMed Abstract: 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.

PubMed: 17973403
DOI: 10.1021/bi701439j

Experimental method

X-RAY DIFFRACTION (1.9 Å)