Structural, biochemical and genetic characterization of dissimilatory ATP sulfurylase from Allochromatium vinosum

PLoS One. 2013 Sep 20;8(9):e74707. doi: 10.1371/journal.pone.0074707. eCollection 2013.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Phosphosulfate / metabolism
  • Adenosine Triphosphate / metabolism*
  • Amino Acid Sequence
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Chromatiaceae / enzymology*
  • Diphosphates / metabolism
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Molecular Sequence Data
  • Protein Conformation
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Sulfate Adenylyltransferase / chemistry*
  • Sulfate Adenylyltransferase / genetics*
  • Sulfate Adenylyltransferase / metabolism
  • Sulfates / metabolism*

Substances

  • Bacterial Proteins
  • Diphosphates
  • Recombinant Proteins
  • Sulfates
  • Adenosine Phosphosulfate
  • diphosphoric acid
  • Adenosine Triphosphate
  • Sulfate Adenylyltransferase

Grants and funding

This work was supported by the Max-Planck Society and the Deutsche Forschungsgemeinschaft. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.