Cargando…

Structural, Biochemical and Genetic Characterization of Dissimilatory ATP Sulfurylase from Allochromatium vinosum

ATP sulfurylase (ATPS) catalyzes a key reaction in the global sulfur cycle by reversibly converting inorganic sulfate (SO(4) (2−)) with ATP to adenosine 5′-phosphosulfate (APS) and pyrophosphate (PP(i)). In this work we report on the sat encoded dissimilatory ATP sulfurylase from the sulfur-oxidizin...

Descripción completa

Detalles Bibliográficos
Autores principales: Parey, Kristian, Demmer, Ulrike, Warkentin, Eberhard, Wynen, Astrid, Ermler, Ulrich, Dahl, Christiane
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3779200/
https://www.ncbi.nlm.nih.gov/pubmed/24073218
http://dx.doi.org/10.1371/journal.pone.0074707
Descripción
Sumario:ATP sulfurylase (ATPS) catalyzes a key reaction in the global sulfur cycle by reversibly converting inorganic sulfate (SO(4) (2−)) with ATP to adenosine 5′-phosphosulfate (APS) and pyrophosphate (PP(i)). 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.