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Title: A New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20

Abstract

To understand the energy conversion activities of the anaerobic sulfate-reducing bacteria, it is necessary to identify the components involved in electron flow. The importance of the abundant type I tetraheme cytochrome c3 (TpIc3) as an electron carrier during sulfate respiration was questioned by the previous isolation of a null mutation in the encoding gene, cycA, in Desulfovibrio alaskensis G20. Whereas respiratory growth of the CycA mutant with lactate and sulfate was little affected, growth with pyruvate and sulfate was significantly impaired. We have explored the phenotype of the CycA mutant through physiological tests and transcriptomic and proteomic analyses. Data reported here show that electrons from pyruvate oxidation do not reach adenylyl sulfate reductase, the enzyme catalyzing the first redox reaction during sulfate reduction, in the absence of either CycAor the type I cytochrome c3:menaquinone oxidoreductase, QrcABCD transmembrane complex. In contrast to the wild type, neither CycA and QrcA mutants do not grow with H2 or formate and sulfate as electron acceptor. Transcriptomic and proteomic analyses of the CycA mutant showed that transcripts and enzymes for the pathway from pyruvate to succinate were strongly decreased in the CycA mutant regardless of growth mode. Neither the CycA nor the QrcA mutant grewmore » on fumarate alone, consistent with the omics results and a redox regulation of gene expression. We conclude that TpIc3 and the Qrc complex are essential D. alaskensis components for transfer of electrons released in the periplasm to reach the cytoplasmic adenylyl sulfate reductase and present a model that may explain the CycA phenotype through confurcation of electrons.« less

Authors:
 [1];  [1];  [2];  [3];  [3];  [2]
  1. University of Missouri, Columbia
  2. University of Missouri
  3. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1115382
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied and Environmental Microbiology
Country of Publication:
United States
Language:
English

Citation Formats

Keller, Kimberly L, Rapp-Giles, Barbara J, Semkiw, Elizabeth M., Porat, Iris, Brown, Steven D, and Wall, Judy D. A New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20. United States: N. p., 2013. Web.
Keller, Kimberly L, Rapp-Giles, Barbara J, Semkiw, Elizabeth M., Porat, Iris, Brown, Steven D, & Wall, Judy D. A New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20. United States.
Keller, Kimberly L, Rapp-Giles, Barbara J, Semkiw, Elizabeth M., Porat, Iris, Brown, Steven D, and Wall, Judy D. Tue . "A New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20". United States. doi:.
@article{osti_1115382,
title = {A New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20},
author = {Keller, Kimberly L and Rapp-Giles, Barbara J and Semkiw, Elizabeth M. and Porat, Iris and Brown, Steven D and Wall, Judy D.},
abstractNote = {To understand the energy conversion activities of the anaerobic sulfate-reducing bacteria, it is necessary to identify the components involved in electron flow. The importance of the abundant type I tetraheme cytochrome c3 (TpIc3) as an electron carrier during sulfate respiration was questioned by the previous isolation of a null mutation in the encoding gene, cycA, in Desulfovibrio alaskensis G20. Whereas respiratory growth of the CycA mutant with lactate and sulfate was little affected, growth with pyruvate and sulfate was significantly impaired. We have explored the phenotype of the CycA mutant through physiological tests and transcriptomic and proteomic analyses. Data reported here show that electrons from pyruvate oxidation do not reach adenylyl sulfate reductase, the enzyme catalyzing the first redox reaction during sulfate reduction, in the absence of either CycAor the type I cytochrome c3:menaquinone oxidoreductase, QrcABCD transmembrane complex. In contrast to the wild type, neither CycA and QrcA mutants do not grow with H2 or formate and sulfate as electron acceptor. Transcriptomic and proteomic analyses of the CycA mutant showed that transcripts and enzymes for the pathway from pyruvate to succinate were strongly decreased in the CycA mutant regardless of growth mode. Neither the CycA nor the QrcA mutant grew on fumarate alone, consistent with the omics results and a redox regulation of gene expression. We conclude that TpIc3 and the Qrc complex are essential D. alaskensis components for transfer of electrons released in the periplasm to reach the cytoplasmic adenylyl sulfate reductase and present a model that may explain the CycA phenotype through confurcation of electrons.},
doi = {},
journal = {Applied and Environmental Microbiology},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 2013},
month = {Tue Jan 01 00:00:00 EST 2013}
}