Year-end Sale % OFF 
Abstract
In the genome of Shewanella oneidensis, genes encoding the global regulators ArcA, Crp, and EtrA have been identified. All these proteins deviate from their counterparts in E. coli significantly in terms of functionality and regulon. It is worth investigating the involvement and relationship of these global regulators in aerobic and anaerobic respiration in S. oneidensis. In this study, the impact of the transcriptional factors ArcA, Crp, and EtrA on aerobic and anaerobic respiration in S. oneidensis were assessed. While all these proteins appeared to be functional in vivo, the importance of individual proteins in these two major biological processes differed. The ArcA transcriptional factor was critical in aerobic respiration while the Crp protein was indispensible in anaerobic respiration. Using a newly developed reporter system, it was found that expression of arcA and etrA was not influenced by growth conditions but transcription of crp was induced by removal of oxygen. An analysis of the impact of each protein on transcription of the others revealed that Crp expression was independent of the other factors whereas ArcA repressed both etrA and its own transcription while EtrA also repressed arcA transcription. Transcriptional levels of arcA in the wild type, crp, and etrA strains under either aerobic or anaerobic conditions were further validated by quantitative immunoblotting with a polyclonal antibody against ArcA. This extensive survey demonstrated that all these three global regulators are functional in S. oneidensis. In addition, the reporter system constructed in this study will facilitate in vivo transcriptional analysis of targeted promoters.
Highlights
Depending on the availability of electron donors and acceptors, facultative anaerobes such as Escherichia coli adopt three different metabolic modes: aerobic respiration, anaerobic respiration, and fermentation [1,2]
We report results from experiments designed to reveal the involvement of three global regulators (ArcA, Crp, and EtrA) in aerobic and anaerobic respiration in S. oneidensis
S. oneidensis MR-1 is an intriguing microorganism in terms of its metabolic pathways
Summary
Depending on the availability of electron donors and acceptors, facultative anaerobes such as Escherichia coli adopt three different metabolic modes: aerobic respiration, anaerobic respiration, and fermentation [1,2]. The switch between aerobic and anaerobic metabolism is controlled primarily by the Fnr (fumarate nitrate regulator) transcription factor and the Arc (aerobic respiration control) two-component regulatory system [3]. Fnr, synthesized under both aerobic and anaerobic conditions, is able to sense oxygen directly using its [4Fe-4S]2+ cluster whereas the Arc system senses oxygen indirectly [4]. After sensing changes in the redox state of the quinone pool elicited by oxygen limitation, ArcB, the sensor kinase of the system, autophosphorylates and transphosphorylates the response regulator ArcA [5,6]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
