An acid-tolerance response system protecting exponentially growing Escherichia coli

Ying Xu, Zhe Zhao, Wenhua Tong, Yamei Ding, Bin Liu, Yixin Shi, Jichao Wang, Shenmei Sun, Min Liu, Yuhui Wang, Qingsheng Qi, Mo Xian (+1 others)
2020 Nature Communications  
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
more » ... on 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 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.
doi:10.1038/s41467-020-15350-5 pmid:32198415 fatcat:eldu653bfncd5ox3lg46oicanq