Stability and repair of DNA in hyperthermophilic Archaea.
Stability and repair of DNA in hyperthermophilic Archaea.
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DOI：
10.21775/cimb.006.137
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发表时间：
2004-07
影响因子：
3.1
通讯作者：
D. Grogan
中科院分区：
文献类型：
--
作者：
D. Grogan
进化和生理的考虑认为，研究超嗜热古菌应该揭示新的DNA稳定和修复的分子方面。到目前为止，这些不寻常的原核生物已经产生了一些基因和酶活性与切除修复，光逆转，和跨病变合成的已知机制一致。然而，超嗜热古菌的其他DNA酶显示出新的生物化学性质，这可能与DNA的稳定性或修复在极高的温度，但仍然难以在体内进行严格的评估。也许极端嗜热古菌最显著的特征是，所有已测序的基因组都缺乏核苷酸切除修复和DNA错配修复途径的关键基因，这些基因在生物学中是高度保守的。虽然这些微生物的生长特性阻碍了实验，但有证据表明，硫化叶菌属中存在一些切除修复和突变避免系统。因此，在今后几年中，制定和检验硫化叶菌属的假设将具有战略意义。和其他极端嗜热古菌有关的机制和基因产物参与修复紫外光产物和DNA错配。
Evolutionary and physiological considerations argue that study of hyperthermophilic archaea should reveal new molecular aspects of DNA stabilization and repair. So far, these unusual prokaryotes have yielded a number of genes and enzymatic activities consistent with known mechanisms of excision repair, photo-reversal, and trans-lesion synthesis. However, other DNA enzymes of hyperthermophilic archaea show novel biochemical properties which may be related to DNA stability or repair at extremely high temperature but which remain difficult to evaluate rigorously in vivo. Perhaps the most striking feature of the hyperthermophilic archaea is that all of them whose genomes have been sequenced lack key genes of both the nucleotide excision repair and DNA mismatch repair pathways, which are otherwise highly conserved in biology. Although the growth properties of these micro-organisms hinder experimentation, there is evidence that some systems of excision repair and mutation avoidance operate in Sulfolobus spp. It will therefore be of strategic significance in the next few years to formulate and test hypotheses in Sulfolobus spp. and other hyperthermophilic archaea regarding mechanisms and gene products involved in the repair of UV photoproducts and DNA mismatches.