Lieph Ryan, Veloso Felipe A, Holmes David S
Center for Bioinformatics and Genome Biology, Millennium Institute of Fundamental and Applied Biology, Life Science Foundation and Andrés Bello University, Av. Zanartu 1482, Santiago, Chile.
Trends Microbiol. 2006 Oct;14(10):423-6. doi: 10.1016/j.tim.2006.08.004. Epub 2006 Aug 28.
A plethora of mechanisms confer protein stability in thermophilic microorganisms and, recently, it was suggested that these mechanisms might be divided along evolutionary lines. Here, a multi-genome comparison shows that there is a statistically significant increase in the proportion of NTN codons correlated with increasing optimal growth temperature for both Bacteria and Archaea. NTN encodes exclusively non-polar, hydrophobic amino acids and indicates a common underlying use of hydrophobicity for stabilizing proteins in Bacteria and Archaea that transcends evolutionary origins. However, some microorganisms do not follow this trend, suggesting that alternate mechanisms (e.g. intracellular electrolytes) might be used for protein stabilization. These studies highlight the usefulness of large-scale comparative genomics to uncover novel relationships that are not immediately obvious from protein structure studies alone.
大量机制赋予嗜热微生物中的蛋白质稳定性，最近有人提出，这些机制可能会按照进化路线进行划分。在这里，一项多基因组比较表明，对于细菌和古菌而言，与最佳生长温度升高相关的NTN密码子比例在统计学上有显著增加。NTN专门编码非极性、疏水性氨基酸，这表明细菌和古菌在利用疏水性稳定蛋白质方面存在共同的潜在用途，且这种用途超越了进化起源。然而，一些微生物并不遵循这一趋势，这表明可能使用了其他机制（如细胞内电解质）来稳定蛋白质。这些研究突出了大规模比较基因组学在揭示仅凭蛋白质结构研究无法立即明确的新关系方面的有用性。
