作者: Roxanne Lestini , Christophe Creze , Didier Flament , Hannu Myllykallio , Ghislaine Henneke
DOI: 10.5772/23361
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摘要: DNA is the carrier of genetic information, but constantly assaulted by endogenous and exogenous genotoxic attacks in all living organisms. If left unrepaired damaged or structurally altered can impede pathways metabolism maintenance genomic stability lead to cell death uncontrolled proliferation. Archaea comprise diverse microorganisms that thrive harsh environments like hydrothermal vents acidic hot springs. They live without sunlight organic carbon as food, instead survive on sulfur hydrogen, other materials most bacteria eukaryotes not metabolize. Considering extreme environmental niches inhabited archaeal species, lesions could be massively induced exposure hazardous factors, (e.g., ultraviolet, Xand -rays, elevated temperatures mutagens, e.g., reactive oxygen/nitrogen alkylating agents toxic metals), very high rates potentially mutagenic (deamination, depurination, oxidation hydrolytic mechanisms, alkylations subsequent strand breakage) are expected arise. However, interestingly, it was demonstrated hyperthermophilic crenarchaeota Sulfolobus Acidocaldarius exhibited a modest rate spontaneous mutations nearly close mesophilic bacteria, Escherichia Coli (E. coli) (Grogan et al., 2001). Similarly, euryarchaeota Pyrococcus abyssi doses ionizing gamma irradiation (Jolivet 2003b) abasic sites formation chromosome found occur at moderately higher than E. coli (Palud 2008). Thus, organisms seem evolve efficient strategies for repairing damage thus avoiding mutations. Like eukaryotes, repair mechanisms include nucleolytic processing DNA. Consequently, this article sets out review nucleases based current knowledge sequence, structure mechanism. We have focused recent work several nucleases, with detailed description substrate preference cleavage specificity these enzymes. Crystal structures, when available, discussed context biochemical data outline mechanistic features, such enzymatic cleavage, binding, sometimes, although always, functions. This stresses molecular which been conserved throughout evolution reference eukaryotic and, some cases,