title: Thiouridine residues in tRNAs are responsible for a synergistic effect of UVA and UVB light in photoinactivation of Escherichia coli.
abstract: Since different wavelengths of light impact different cellular targets, microorganisms exposed to natural sunlight experience a combination of multiple stressors. In order to better understand the effects of sunlight on microorganisms we, therefore, need to understand how different wavelength act alone and in combination. Here, we describe a synergistic effect between UVA and UVB irradiation on viability of Escherichia coli bacteria. To investigate the basis of this synergistic effect we analysed mutant strains that were obtained through selection for increased resistance to combined UVA and UVB. By identifying and reconstructing genetic changes in the resistant strains we provide evidence that UVA-absorbing thiouridine residues in tRNAs are the key to the synergistic effect. Our study provides insights into how naturally occurring combinations of stressors can interact, and points to new ways for controlling microbial populations.
authors.affiliation: Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, Zurich, Switzerland.|Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Probst-Rüd
authors.affiliation: Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, Zurich, Switzerland.
authors.forename: Kristopher
authors.initials: K
authors.lastname: McNeill
authors.affiliation: Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, Zurich, Switzerland.|Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Ackermann
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects*; D050296:Microbial Viability / Q000528:radiation effects; D012343:RNA, Transfer / Q000737:chemistry / Q000528:radiation effects*; D011836:Radiation Tolerance; D013472:Sunlight; D013891:Thiouridine / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D013891:Thiouridine; D012343:RNA, Transfer