Purification, crystallization and preliminary X-ray analysis of the dissimilatory sulfite reductase from Desulfovibrio vulgaris Miyazaki F.

Dissimilatory sulfite reductase (Dsr) plays an important role in sulfate respiration in many sulfate-reducing bacteria. Dsr from Desulfovibrio vulgaris Miyazaki F has been purified and crystallized at 277†K using the sitting-drop vapour-diffusion method with PEG 3350 and potassium thiocyanate as precipitants. A data set was collected to 3.7†à resolution from a single crystal at 100†K using synchrotron radiation. The Dsr crystal belonged to space group P4(1)2(1)2, with unit-cell parameters a = b = 163.26, c = 435.32†à . The crystal structure of Dsr was determined by the molecular-replacement method based on the three-dimensional structure of Dsr from D. vulgaris Hildenborough. The crystal contained three α(2)β(2)γ(2) units per asymmetric unit, with a Matthews coefficient (V(M)) of 2.35†à (3)†Da(-1); the solvent content was estimated to be 47.7%.