11月26日，英國著名雜志《核酸研究》（nuclear acid research ）在線發(fā)表了中科院上海生命科學(xué)研究院生物化學(xué)與細胞生物學(xué)研究所丁建平組最新研究成果,。文章闡述了色氨酰和酪氨酰tRNA合成酶的進化關(guān)系,，解決了長久以來的爭論,。該論文受到了審稿專家和編輯的高度贊賞,。他們認為其原創(chuàng)性和重要性列于該期論文中前5%,，因而被推薦為該期雜志的專題文章（feature article）,。
氨酰tRNA合成酶負責將特定的氨基酸轉(zhuǎn)移到相應(yīng)的tRNA分子的氨基酸接受臂上,，保證蛋白的正確翻譯,。它是進化史中出現(xiàn)較早的一類酶，故而經(jīng)常被用來分析早期的進化事件,。由于色氨酰和酪氨酰tRNA合成酶的序列同源性較低,，對兩者的進化關(guān)系一直存有爭議。然而這兩類酶的結(jié)構(gòu)相似度較高,，所以基于結(jié)構(gòu)的進化分析更為適合研究它們的進化關(guān)系,。丁建平組博士生董咸池和周旻昀等人解析了首個來源于古細菌的色氨酰tRNA合成酶的晶體結(jié)構(gòu)，并利用該結(jié)構(gòu)進行了基于結(jié)構(gòu)的進化分析,。該研究首次包含了分別代表生物界三界（真細菌,、古細菌和真核生物）的生物體的色氨酰和酪氨酰tRNA合成酶的晶體結(jié)構(gòu)，因而相比以往的TrpRS進化分析具有較高的可靠性,。研究結(jié)果揭示了色氨酰tRNA合成酶起源于古細菌的酪氨酰tRNA合成酶,，解決了長期以來關(guān)于色氨酰tRNA合成酶起源的爭論。
該項研究工作得到了國家科技部,、國家自然科學(xué)基金委,、中國科學(xué)院及上海市科委的經(jīng)費支持。（生物谷Bioon.com）
生物谷推薦原始出處：
Nucleic Acids Research, doi:10.1093/nar/gkp1053
Crystal structure of Pyrococcus horikoshii tryptophanyl-tRNA synthetase and structure-based phylogenetic analysis suggest an archaeal origin of tryptophanyl-tRNA synthetase
Xianchi Dong1,2, Minyun Zhou1,2, Chen Zhong1, Bei Yang1,2, Ning Shen1 and Jianping Ding1,*
1State Key Laboratory of Molecular Biology and Research Center for Structural Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and 2Graduate School of Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
The ancient and ubiquitous aminoacyl-tRNA synthetases constitute a valuable model system for studying early evolutionary events. So far, the evolutionary relationship of tryptophanyl- and tyrosyl-tRNA synthetase (TrpRS and TyrRS) remains controversial. As TrpRS and TyrRS share low sequence homology but high structural similarity, a structure-based method would be advantageous for phylogenetic analysis of the enzymes. Here, we present the first crystal structure of an archaeal TrpRS, the structure of Pyrococcus horikoshii TrpRS (pTrpRS) in complex with tryptophanyl-5' AMP (TrpAMP) at 3.0 ? resolution which demonstrates more similarities to its eukaryotic counterparts. With the pTrpRS structure, we perform a more complete structure-based phylogenetic study of TrpRS and TyrRS, which for the first time includes representatives from all three domains of life. Individually, each enzyme shows a similar evolutionary profile as observed in the sequence-based phylogenetic studies. However, TyrRSs from Archaea/Eucarya cluster with TrpRSs rather than their bacterial counterparts, and the root of TrpRS locates in the archaeal branch of TyrRS, indicating the archaeal origin of TrpRS. Moreover, the short distance between TrpRS and archaeal TyrRS and that between bacterial and archaeal TrpRS, together with the wide distribution of TrpRS, suggest that the emergence of TrpRS and subsequent acquisition by Bacteria occurred at early stages of evolution.
