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Novel Regulatory Cascades Controlling Expression of Nitrogen Fixation Genes
Nucleic Acids Research (2010)
  • Toshiyuki Ueki
  • Derek Lovley, University of Massachusetts - Amherst

Geobacter species often play an important role in bioremediation of environments contaminated with metals or organics and show promise for harvesting electricity from waste organic matter in microbial fuel cells. The ability of Geobacter species to fix atmospheric nitrogen is an important metabolic feature for these applications. We identified novel regulatory cascades controlling nitrogen-fixation gene expression in Geobacter sulfurreducens. Unlike the regulatory mechanisms known in other nitrogen-fixing microorganisms, nitrogen-fixation gene regulation in G. sulfurreducens is controlled by two two-component His-Asp phosphorelay systems. One of these systems appears to be the master regulatory system that activates transcription of the majority of nitrogen-fixation genes and represses a gene encoding glutamate dehydrogenase during nitrogen fixation. The other system whose expression is directly activated by the master regulatory system appears to control by antitermination the expression of a subset of the nitrogen-fixation genes whose transcription is activated by the master regulatory system and whose promoter contains transcription termination signals. This study provides a new paradigm for nitrogen-fixation gene regulation.

Publication Date
July 24, 2010
Publisher Statement

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.

DOI: 10.1093/nar/gkq652

The published version is located at
Citation Information
Toshiyuki Ueki and Derek Lovley. "Novel Regulatory Cascades Controlling Expression of Nitrogen Fixation Genes" Nucleic Acids Research Vol. 38 Iss. 21 (2010)
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