Crystallization and preliminary X-ray analysis of NAD kinase from Mycobacterium tuberculosis H37Rv

NAD kinase from Mycobacterium tuberculosis H37Rv utilizes ATP or inorganic polyphosphate [poly(P)] as a phosphoryl donor for the phosphorylation of NA D. The enzyme overexpressed in Escherichia coli was purified and crystalliz ed by means of the hanging-drop vapour-diffusion method with polyethylene g lycol 4000 as the precipitant. Preliminary X-ray analysis of the resultant crystals revealed they belonged to the monoclinic space group C2 and had un it-cell parameters a = 140.0, b = 69.3, c = 106.3 Angstrom, beta = 130.1 de grees. The molecular weight of the NAD kinase is 35 kDa; assuming that a cr ystal contains two subunits of the NAD kinase in an asymmetric unit, the so lvent content V-sol is 0.62. X-ray diffraction data to 2.99 Angstrom have b een collected from the native crystal.