Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of DsrEFH from Allochromatium vinosum.

In purple sulfur bacteria, the proteins encoded by dsr genes play an essential role in the oxidation of intracellular sulfur, which is an obligate intermediate during the oxidation of sulfide and thiosulfate. One such gene product, DsrEFH from Allochromatium vinosum, has been cloned, expressed, purified and crystallized. Synchrotron data were collected to 2.5 A from a crystal of selenomethionine-substituted DsrEFH. The crystal belongs to the primitive monoclinic space group P2(1), with unit-cell parameters a = 56.6, b = 183.1, c = 107.8 A, beta = 99.6 degrees. A full structure determination is under way in order to provide insight into the structure-function relationships of this protein.