Crystallization and preliminary X-ray crystallographic analysis of 2-methyl-3-hydroxypyridine-5-carboxylic acid (MHPC) oxygenase from Pseudomonas sp. MA-1

2-Methyl-3-hydroxypyridine-5-carboxylic acid (MHPC) oxygenase (MHPCO) catalyzes the conversion of an aromatic substrate, MHPC, to an aliphatic compound, α-(N-acetylaminomethylene)-succinic acid, and is involved in the degradation of vitamin B₆ by the soil bacterium Pseudomonas sp. MA-1. Using only FAD as a cofactor, MHPCO is unique in catalyzing hydroxylation and subsequent aromatic ring cleavage without requiring a metal-ion cofactor. Here, the crystallization of MHPCO is reported together with preliminary X-ray crystallographic data. An MHPCO crystal obtained by hanging-drop vapour diffusion diffracted X-rays to 2.25 Å resolution and belonged to the triclinic space group P1, with four molecules per asymmetric unit.