An acid-tolerance response system protecting exponentially growing Escherichia coli

• Published in: Nature communications Vol. 11; no. 1; p. 1496
• Main Authors: Xu, Ying, Zhao, Zhe, Tong, Wenhua, Ding, Yamei, Liu, Bin, Shi, Yixin, Wang, Jichao, Sun, Shenmei, Liu, Min, Wang, Yuhui, Qi, Qingsheng, Xian, Mo, Zhao, Guang
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 20.03.2020; Nature Publishing Group UK; Nature Portfolio
• Subjects: 3-Oxoacyl-(Acyl-Carrier-Protein) Synthase - genetics; 3-Oxoacyl-(Acyl-Carrier-Protein) Synthase - metabolism; Acid resistance; Acidification; Adenosine triphosphatase; Animals; Bacteria; Bacterial Proteins - metabolism; Base Sequence; Binding Sites; Circuits; Colonization; Drug Tolerance - physiology; E coli; Escherichia coli; Escherichia coli - genetics; Escherichia coli - growth & development; Escherichia coli - metabolism; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; F0F1-ATPase; Fatty Acid Synthase, Type II - genetics; Fatty Acid Synthase, Type II - metabolism; Fatty acids; Fatty Acids, Unsaturated - metabolism; Female; Fermentation; Fluidity; Gene Expression Regulation, Bacterial; Gram-negative bacteria; Histidine; Homeostasis; Hydro-Lyases - genetics; Hydro-Lyases - metabolism; Hydrogen-Ion Concentration; Intestine; Intestines - microbiology; Lactic Acid - analogs & derivatives; Lactic Acid - metabolism; Lipid composition; Lipids; Membrane Fluidity; Membrane Lipids; Mice; Mice, Inbred BALB C; pH effects; Protein Kinases - metabolism; Protonation; Survival; Transcription, Genetic
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-15350-5

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 F -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.