An acid-tolerance response system protecting exponentially growing Escherichia coli.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32198415.
- Also identified by DOI 10.1038/s41467-020-15350-5 and PMC identifier 7083825.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The ability to grow at moderate acidic conditions (pH 4.0-5.0) is important to Escherichia coli colonization of the host's intestine. Several regulatory systems are known to control acid resistance in E. coli, enabling the bacteria to survive under acidic conditions without growth. Here, we characterize an acid-tolerance response (ATR) system and its regulatory circuit, required for E. coli exponential growth at pH 4.2. A two-component system CpxRA directly senses acidification through protonation of CpxA periplasmic histidine residues, and upregulates the fabA and fabB genes, leading to increased production of unsaturated fatty acids. Changes in lipid composition decrease membrane fluidity, F<sub>0</sub>F<sub>1</sub>-ATPase activity, and improve intracellular pH homeostasis. The ATR system is important for E. coli survival in the mouse intestine and for production of higher level of 3-hydroxypropionate during fermentation. Furthermore, this ATR system appears to be conserved in other Gram-negative bacteria.
Medical subject headings
- Drug Tolerance
- Escherichia coli