An integrated network analysis identifies how ArcAB enables metabolic oscillations in the nitric oxide detoxification network of Escherichia coli.

TitleAn integrated network analysis identifies how ArcAB enables metabolic oscillations in the nitric oxide detoxification network of Escherichia coli.
Publication TypeJournal Article
Year of Publication2017
AuthorsSacco, SA, Adolfsen, KJ, Brynildsen, MP
JournalBiotechnol J
Volume12
Issue8
Date Published2017 Aug
ISSN1860-7314
KeywordsAerobiosis, Bacterial Outer Membrane Proteins, Catalysis, Escherichia coli, Escherichia coli Proteins, Gene Expression Regulation, Bacterial, Inactivation, Metabolic, Membrane Proteins, Nitric Oxide, Oxygen, Oxygenases, Protein Kinases, Repressor Proteins
Abstract

<p>The virulences of many pathogens depend on their abilities to detoxify the immune antimicrobial nitric oxide (NO•). The functions of bacterial NO• detoxification machinery depend on oxygen (O ), with O inhibiting some enzymes, whereas others use it as a substrate. Previously, Escherichia coli NO• detoxification was found to be highly attenuated under microaerobic conditions and metabolic oscillations were observed. The oscillations in [NO•] and [O ] were found to result from the inhibitory action of NO• on aerobic respiration, the catalytic inactivation of NO• by Hmp (an NO• dioxygenase), and an imbalanced competition for O between Hmp and cytochrome terminal oxidase activity. Here the authors investigated the role of the ArcAB two component system (TCS) in microaerobic NO• detoxification. The authors observed that wild-type, ΔarcA, and ΔarcB had comparable initial NO• clearance times; however, the mutant cultures failed to exhibit [NO•] and [O ] oscillations. Using an approach that employed experimentation and computational modeling, the authors found that the loss of oscillations in ΔarcA was due to insufficient induction of cytochrome bd-I expression. Collectively, these results establish ArcAB as a TCS that influences NO• detoxification in E. coli within the physiologically-relevant microaerobic regime.</p>

DOI10.1002/biot.201600570
Alternate JournalBiotechnol J
PubMed ID28449226