Affiliation:
1. Department of Biochemistry and Biophysics, University of California, Davis 95616.
Abstract
proU expression has been proposed to form part of a general stress response that is regulated by increased negative DNA supercoiling brought about by environmental signals such as osmotic or anaerobic stress (N. Ni Bhriain, C. J. Dorman, and C. F. Higgins, Mol. Microbiol. 3:933-944, 1989). However, we find that although proU-containing plasmids derived from cells grown in media of elevated osmolarity were more supercoiled than plasmids from cells grown in standard media, they did not activate proU expression in vitro. The gyrA96 mutation and anaerobic conditions are known to affect DNA supercoiling but did not alter proU expression. Finally, the gyrase inhibitors coumermycin and novobiocin did not reduce in vitro proU expression. Therefore, this evidence rules out regulation by changes in DNA superhelicity for proU in Escherichia coli.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference55 articles.
1. Regulation of envelope composition during adaptation to osmotic stress in Escherichia coli;Barron A.;J. Bacteriol.,1986
2. Osmoregulation of gene expression in Salmonella typhimurium: proU encodes an osmotically induced betaine transport system;Cairney J.;J. Bacteriol.,1985
3. Transposition and fusion of the lac genes to selected promoters in Escherichia coli using bacteriophage lambda and Mu;Casadaban M. J.;J. Mol. Biol.,1976
4. Cashel M. and K. E. Rudd. 1987. The stringent response p. 1410-1438. In F. C. Neidhardt J. L. Ingraham K. B. Low B. Magasanik M. Schaechter and H. E. Umbarger (ed.) Escherichia coli and Salmonella typhimurium: cellular and molecular biology vol. 2. American Society for Microbiology Washington D.C.
5. Physiological and genetic responses of bacteria to osmotic stress;Csonka L. N.;Microbiol. Rev.,1989
Cited by
27 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献