Expression, purification, crystallization and preliminary X-ray analysis of the acyl carrier protein synthase (acpS) from Mycobacterium tuberculosis.

Acyl carrier protein synthase (acpS) catalyzes the formation of holo-ACP, which mediates the transfer of acyl fatty-acid intermediates during the biosynthesis of fatty acids and lipids. An expression and purification system for the Mycobacterium tuberculosis (Mtb) acpS has been established that yields approximately 15 mg l(-1) of the enzyme in soluble form. The purified enzyme has been crystallized by the vapour-diffusion method using 2-propanol as a precipitant. The original crystal size has been improved significantly by the addition of glycerol to the mother liquor. Mtb acpS crystals belong to the space group R3, with unit-cell parameters a = b = 68.53, c = 85.9 A. Native data have been collected under cryogenic conditions; phase resolution by molecular replacement and selenomethionine-aided multi-wavelength anomalous dispersion techniques is ongoing.