An acid-tolerance response system protecting exponentially growing Escherichia coli.

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, F₀F₁-ATPase activity, and improve intracellular pH homeostasis. The ATR syste

SUBMITTER: Xu Y 

PROVIDER: S-EPMC7083825 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature