Purification, crystallization and preliminary X-ray analysis of 3-hydroxy-3-methylglutaryl-coenzyme A reductase of Streptococcus pneumoniae

Class II 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductases are potential targets for novel antibiotic development. In order to obtain a precise structural model for use in virtual screening and inhibitor design, HMG-CoA reductase of Streptococcus pneumoniae was cloned, overexpressed and purified to homogeneity using Ni-NTA affinity chromatography. Crystals were obtained using the hanging-drop vapour-diffusion method. A complete data set was collected from a single frozen crystal on a home X-ray source. The crystal diffracted to 2.3 A resolution and belonged to the orthorhombic space group C222(1), with unit-cell parameters a = 773.4836, b = 90.3055, c = 160.5592 A, alpha = beta = gamma = 90 degrees. Assuming the presence of two molecules in the asymmetric unit, the solvent content was estimated to be 54.1% (V (M) = 2.68 A3 Da-1).