Crystallization and preliminary X-ray diffraction studies of phospho-adenylylsulfate (PAPS) reductase from E. coli.

PAPS reductase from E. coli is involved in sulfur metabolism and catalyses the reduction of phospho-adenylyl-sulfate (PAPS) to sulfite. The protein has been cloned, overexpressed and purified from E. coli. Crystallization experiments resulted in crystals suitable for X-ray diffraction. The crystals belong to the orthorhombic space group C2221 with cell dimensions a = 81.9, b = 97.4, c = 109.5 A, and contain one molecule per asymmetric unit. At cryogenic (100 K) temperatures the crystals diffract to a resolution limit of 2.7 A using a rotating anode and to 2.0 A at a synchrotron source.