Expression, purification, crystallization and initial crystallographic characterization of the p-hydroxybenzoate hydroxylase from Corynebacterium glutamicum

p-Hydroxybenzoate hydroxylase (PHBH) is an FAD-dependent mono-oxygenase that catalyzes the hydroxylation of p-hydroxybenzoate (pOHB) to 3,4-dihydroxybenzoate in an NADPH-dependent reaction and plays an important role in the biodegradation of aromatic compounds. PHBH from Corynebacterium glutamicum was crystallized using the hanging-drop vapour-diffusion method in the presence of NaH₂PO₄ and K₂HPO₄ as precipitants. X-ray diffraction data were collected to a maximum resolution of 2.5 Å on a synchrotron beamline. The crystal belongs to the hexagonal space group P6₃22, with unit-cell parameters a = b = 94.72, c = 359.68 Å, γ = 120°. The asymmetric unit contains two molecules, corresponding to a packing density of 2.65 ų Da^-1. The structure was solved by molecular replacement. Structure refinement is in progress.