Cloning, expression, purification, crystallization and X-ray crystallographic analysis of Rv2606c from Mycobacterium tuberculosis H37Rv

Tuberculosis is a widespread and deadly infectious disease, and one third of the human population is already infected. Vitamin B₆ is known to be synthesized through consecutive reactions mediated by pyridoxal biosynthesis lyase (PdxS) and glutamine amidotransferase (PdxT). The gene product Rv2606c, the PdxS pyridoxal biosynthesis lyase from Mycobacterium tuberculosis, was crystallized using the hanging-drop vapour-diffusion method in the presence of 8%(w/v) PEG 8000, 0.1 M 3-(cyclohexylamino)-1-propanesulfonic acid pH 10.5 and 0.2 M sodium chloride at 295 K. X-ray diffraction data were collected to a maximum resolution of 1.7 Å on a synchrotron beamline. The crystal belonged to space group I222 or I2₁2₁2₁, with unit-cell parameters a = 110.75, b = 126.08, c = 180.82 Å, α = β = γ = 90°. With three molecules per asymmetric unit, the crystal volume per unit protein weight (V_M) was 3.79 ų Da⁻¹.