title: Increased ultraviolet radiation sensitivity of Escherichia coli grown at low temperature.
abstract: The repair of DNA damage caused by ultraviolet radiation (UVR) is well understood in both lower and higher organisms. Genetic studies carried out at optimum temperature for growth, 37 °C in Escherichia coli, have revealed the major pathways of DNA repair. We show that E. coli cells grown at 20 °C are more sensitive to UVR than cells grown at 37 °C. The analysis of knockout mutants demonstrates that cells impaired in recombinational DNA repair pathways show increased UV sensitivity at 20 °C. Cells with mutations in the nucleotide excision repair (NER) pathway genes are highly sensitive to UVR when grown at 37 °C and retain that sensitivity when grown at 20 °C, whereas wild-type cells are not sensitive when grown at 37 °C but become more sensitive to UVR when grown at low temperatures. Our results taken along with reports from the literature suggest that the UVR sensitivity of E. coli cells at low temperature could be due to impaired NER function.
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
authors.forename: Suhas
authors.initials: S
authors.lastname: Mangoli
authors.forename: Devashish
authors.initials: D
authors.lastname: Rath
authors.forename: Manish
authors.initials: M
authors.lastname: Goswami
authors.forename: Narendra
authors.initials: N
authors.lastname: Jawali
mesh_terms: D003080:Cold Temperature; D004249:DNA Damage; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects*; D009154:Mutation; D013696:Temperature; D014466:Ultraviolet Rays
keywords: Escherichia coli; basse température; low temperature; nucleotide excision repair pathway; rayonnement ultraviolet; survie; survival; ultraviolet radiation; voie de réparation par excision de nucléotides