UV photoreactions of the extremely haloalkaliphilic euryarchaeon Natronomonas pharaonis.
The objective of this study was to investigate the photobiological responses of the haloalkaliphilic euryarchaeon Natronomonas pharaonis to environmentally relevant polychromatic UV radiation, simulating either the present UV radiation climate (lambda>290 nm) or that of the early Earth (lambda>220 nm), and to monochromatic UVC radiation (lambda=254 nm) for comparison with the literature data. UV-induced bipyrimidine DNA photoproducts were determined using a sensitive and accurate HPLC tandem mass spectrometry assay, allowing to identify and quantify each type of photoproducts formed in the DNA of a UV-irradiated halophilic archaeon. The thymine cytosine (TC) pyrimidine (6-4) pyrimidone photoproduct and the TC cyclobutane pyrimidine dimer accounted for almost 80% of the total induced DNA photolesions, regardless of the wavelength range tested. These prominent formation rates of TC photoproducts correlated with the genomic frequencies of TC dinucleotides in N. pharaonis.
Moeller
Ralf
R
Radiation Biology Department, German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany. ralf.moeller@dlr.de
Reitz
Günther
G
Douki
Thierry
T
Cadet
Jean
J
Horneck
Gerda
G
Stan-Lotter
Helga
H
D002851:Chromatography, High Pressure Liquid; D004249:DNA Damage; D019641:DNA, Archaeal / Q000032:analysis; D006216:Halobacteriaceae / Q000528:radiation effects*; D050296:Microbial Viability; D011740:Pyrimidine Dimers / Q000032:analysis*; D053719:Tandem Mass Spectrometry; D014466:Ultraviolet Rays
D019641:DNA, Archaeal; D011740:Pyrimidine Dimers