title: Integration host factor is required for the induction of acid resistance in Escherichia coli.
abstract: Integration host factor (IHF) is a heterodimeric histone-like DNA-binding protein that participates in many cellular functions. Many systems and global regulators of acid resistance (AR) under strongly acidic conditions have been reported, but the role of IHF has not been examined. In the present study, we report that IHF is necessary for the induction of AR in Escherichia coli. At acidic pH, a ∆ihfA∆ifhB-mutant strain was found to have significantly depressed levels of transcription of the arginine decarboxylase gene (adiA) and of translation of the lysine/cadaverine antiporter gene (cadB), when compared with wild-type strain. Thus, IHF induces the arginine- and lysine-dependent AR. These results indicate that in E. coli, by combined transcriptional and translational controls of gene expression, IHF activates expression of a specific set of genes required for survival at extremely acidic pH.
authors.affiliation: Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 South Goodwin Ave, Urbana, IL, 61801, USA, hkbi@illinois.edu.
authors.forename: Hongkai
authors.initials: H
authors.lastname: Bi
authors.forename: Changyi
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000143:Acids / Q000633:toxicity*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D006863:Hydrogen-Ion Concentration; D034982:Integration Host Factors / Q000235:genetics / Q000378:metabolism*; D050296:Microbial Viability / Q000187:drug effects; D013312:Stress, Physiological
chemical_list: D000143:Acids; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; C440502:integration host factor, E coli