Evolvability of Thermophilic Proteins from Archaea and Bacteria

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• 作者：Kazufumi Takano ; Atsushi Aoi ; Yuichi Koga ; Shigenori Kanaya
• 刊名：Biochemistry
• 出版年：2013
• 出版时间：July 16, 2013
• 年：2013
• 卷：52
• 期：28
• 页码：4774-4780
• 全文大小：367K
• 年卷期：v.52,no.28(July 16, 2013)
• ISSN：1520-4995

文摘

Proteins from thermophiles possess high thermostability. The stabilization mechanisms differ between archaeal and bacterial proteins, whereby archaeal proteins are mainly stabilized via hydrophobic interactions and bacterial proteins by ion pairs. High stability is an important factor in promoting protein evolution, but the precise means by which different stabilization mechanisms affect the evolution process remain unclear. In this study, we investigated a random mutational drift of esterases from thermophilic archaea and bacteria at high temperatures. Our results indicate that mutations in archaeal proteins lead to improved function with no loss of stability, while mutant bacterial proteins are largely destabilized with decreased activity at high temperatures. On the basis of these findings, we suggest that archaeal proteins possess higher 鈥渆volvability鈥?than bacterial proteins under temperature selection and are additionally able to evolve into eukaryotic proteins.