Chromosome and plasmid-borne P_LacO3O1 promoters differ in sensitivity to critically low temperatures.

ABSTRACT: Temperature shifts trigger genome-wide changes in Escherichia coli's gene expression. We studied if chromosome integration impacts on a gene's sensitivity to these shifts, by comparing the single-RNA production kinetics of a P_LacO3O1 promoter, when chromosomally-integrated and when single-copy plasmid-borne. At suboptimal temperatures their induction range, fold change, and response to decreasing temperatures are similar. At critically low temperatures, the chromosome-integrated promoter becomes weaker and noisier. Dissection of its initiation kinetics reveals longer lasting states preceding open complex formation, suggesting enhanced supercoiling buildup. Measurements with Gyrase and Topoisomerase I inhibitors suggest hindrance to escape supercoiling buildup at low temperatures

SUBMITTER: Oliveira SMD 

PROVIDER: S-EPMC6418193 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature