Induction of stress proteins in response to heat shock was found to be reduced significantly in Escherichia coli with ΔtopA mutation. RNase H overexpression in the ΔtopA mutant partially restored the σ32-dependent induction of stress genes in response to high temperature and ethanol. The presence of overexpressed RNase H also improved the survival rate of the ΔtopA mutant after high temperature and oxidative challenges. Topoisomerase I is likely required during stress response for preventing accumulation of transcription-driven hypernegative supercoiling and R-loop formation at induced stress genes loci. © 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
Cheng, B., Rui, S., Ji, C., Gong, V. W., Van Dyk, T. K., Drolet, M., & Tse-Dinh, Y. C. (2003). RNase H overproduction allows the expression of stress-induced genes in the absence of topoisomerase I. FEMS Microbiology Letters, 221(2), 237–242. https://doi.org/10.1016/S0378-1097(03)00209-X