DMCA
Deinococcus geothermalis: the pool of extreme radiation resistance genes shrinks (2007)
| Venue: | PLoS ONE |
| Citations: | 14 - 0 self |
BibTeX
@ARTICLE{Makarova07deinococcusgeothermalis:,
author = {Kira S Makarova and Marina V Omelchenko and Elena K Gaidamakova and Vera Y Matrosova and Alexander Vasilenko and Min Zhai and Alla Lapidus and Alex Copeland and Edwin Kim and Miriam Land and Konstantinos Mavrommatis and Samuel Pitluck and Paul M Richardson and Chris Detter and Thomas Brettin and Elizabeth Saunders and Barry Lai and Bruce Ravel and Kenneth M Kemner and Yuri I Wolf and Alexander Sorokin and Anna V Gerasimova and Mikhail S Gelfand and James K Fredrickson and Eugene V Koonin and Michael J Daly},
title = {Deinococcus geothermalis: the pool of extreme radiation resistance genes shrinks},
journal = {PLoS ONE},
year = {2007},
pages = {955}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at its optimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stressresistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the DeinococcusThermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to resistance; and strengthen the case for a role in survival of systems involved in manganese and iron homeostasis.
