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

摘要

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 Å resolution from a single crystal at 100 K using synchrotron radiation. The Dsr crystal belonged to space group P4₁2₁2, with unit-cell parameters a = b = 163.26, c = 435.32 Å. 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 ₂β₂₂ units per asymmetric unit, with a Matthews coefficient (V_M) of 2.35 Å3 Da−1; the solvent content was estimated to be 47.7%.