4dnx

Publication Abstract from PubMed

ATP sulfurylase (ATPS) catalyzes a key reaction in the global sulfur cycle by reversibly converting inorganic sulfate (SO4 (2-)) with ATP to adenosine 5'-phosphosulfate (APS) and pyrophosphate (PPi). In this work we report on the sat encoded dissimilatory ATP sulfurylase from the sulfur-oxidizing purple sulfur bacterium Allochromatium vinosum. In this organism, the sat gene is located in one operon and co-transcribed with the aprMBA genes for membrane-bound APS reductase. Like APS reductase, Sat is dispensible for growth on reduced sulfur compounds due to the presence of an alternate, so far unidentified sulfite-oxidizing pathway in A. vinosum. Sulfate assimilation also proceeds independently of Sat by a separate pathway involving a cysDN-encoded assimilatory ATP sulfurylase. We produced the purple bacterial sat-encoded ATP sulfurylase as a recombinant protein in E. coli, determined crucial kinetic parameters and obtained a crystal structure in an open state with a ligand-free active site. By comparison with several known structures of the ATPS-APS complex in the closed state a scenario about substrate-induced conformational changes was worked out. Despite different kinetic properties ATPS involved in sulfur-oxidizing and sulfate-reducing processes are not distinguishable on a structural level presumably due to the interference between functional and evolutionary processes.

Structural, biochemical and genetic characterization of dissimilatory ATP sulfurylase from Allochromatium vinosum.,Parey K, Demmer U, Warkentin E, Wynen A, Ermler U, Dahl C PLoS One. 2013 Sep 20;8(9):e74707. doi: 10.1371/journal.pone.0074707. eCollection, 2013. PMID:24073218^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.