Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Nitrosative stress in Escherichia coli : reduction of nitric oxide

Nitrosative stress in Escherichia coli : reduction of nitric oxide The ability of enteric bacteria to protect themselves against reactive nitrogen species generated by their own metabolism, or as part of the innate immune response, is critical to their survival. One important defence mechanism is their ability to reduce NO (nitric oxide) to harmless products. The highest rates of NO reduction by Escherichia coli K-12 were detected after anaerobic growth in the presence of nitrate. Four proteins have been implicated as catalysts of NO reduction: the cytoplasmic sirohaem-containing nitrite reductase, NirB; the periplasmic cytochrome c nitrite reductase, NrfA; the flavorubredoxin NorV and its associated oxidoreductase, NorW; and the flavohaemoglobin, Hmp. Single mutants defective in any one of these proteins and even the mutant defective in all four proteins reduced NO at the same rate as the parent. Clearly, therefore, there are mechanisms of NO reduction by enteric bacteria that remain to be characterized. Far from being minor pathways, the currently unknown pathways are adequate to sustain almost optimal rates of NO reduction, and hence potentially provide significant protection against nitrosative stress. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Biochemical Society Transactions Portland Press

Nitrosative stress in Escherichia coli : reduction of nitric oxide

3 pages

Loading next page...
 
/lp/portland-press/nitrosative-stress-in-escherichia-coli-reduction-of-nitric-oxide-slBscgMyAN

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Portland Press
Copyright
Copyright by Portland Press
ISSN
0300-5127
DOI
10.1042/BST0390213
pmid
21265775
Publisher site
See Article on Publisher Site

Abstract

The ability of enteric bacteria to protect themselves against reactive nitrogen species generated by their own metabolism, or as part of the innate immune response, is critical to their survival. One important defence mechanism is their ability to reduce NO (nitric oxide) to harmless products. The highest rates of NO reduction by Escherichia coli K-12 were detected after anaerobic growth in the presence of nitrate. Four proteins have been implicated as catalysts of NO reduction: the cytoplasmic sirohaem-containing nitrite reductase, NirB; the periplasmic cytochrome c nitrite reductase, NrfA; the flavorubredoxin NorV and its associated oxidoreductase, NorW; and the flavohaemoglobin, Hmp. Single mutants defective in any one of these proteins and even the mutant defective in all four proteins reduced NO at the same rate as the parent. Clearly, therefore, there are mechanisms of NO reduction by enteric bacteria that remain to be characterized. Far from being minor pathways, the currently unknown pathways are adequate to sustain almost optimal rates of NO reduction, and hence potentially provide significant protection against nitrosative stress.

Journal

Biochemical Society TransactionsPortland Press

Published: Feb 1, 2011

Keywords: anaerobiosis, Escherichia coli, nitric oxide, nitric oxide reductase, nitrosative stress

References