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An integrated network analysis identifies how ArcAB enables metabolic oscillations in the nitric oxide detoxification network of Escherichia coli
Author(s) -
Sacco Sarah A.,
Adolfsen Kristin J.,
Brynildsen Mark P.
Publication year - 2017
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.201600570
Subject(s) - detoxification (alternative medicine) , escherichia coli , nitric oxide , biology , cytochrome , biochemistry , mutant , microbiology and biotechnology , enzyme , oxidase test , chemistry , gene , medicine , alternative medicine , pathology , endocrinology
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 2 ), with O 2 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 2 ] 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 2 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, Δ arcA , and Δ arcB had comparable initial NO• clearance times; however, the mutant cultures failed to exhibit [NO•] and [O 2 ] oscillations. Using an approach that employed experimentation and computational modeling, the authors found that the loss of oscillations in Δ arcA 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.