11月26日，英国著名杂志《核酸研究》（nuclear acid research ）在线发表了中科院上海生命科学研究院生物化学与细胞生物学研究所丁建平组最新研究成果。文章阐述了色氨酰和酪氨酰tRNA合成酶的进化关系，解决了长久以来的争论。该论文受到了审稿专家和编辑的高度赞赏。他们认为其原创性和重要性列于该期论文中前5%，因而被推荐为该期杂志的专题文章（feature article）。
氨酰tRNA合成酶负责将特定的氨基酸转移到相应的tRNA分子的氨基酸接受臂上，保证蛋白的正确翻译。它是进化史中出现较早的一类酶，故而经常被用来分析早期的进化事件。由于色氨酰和酪氨酰tRNA合成酶的序列同源性较低，对两者的进化关系一直存有争议。然而这两类酶的结构相似度较高，所以基于结构的进化分析更为适合研究它们的进化关系。丁建平组博士生董咸池和周旻昀等人解析了首个来源于古细菌的色氨酰tRNA合成酶的晶体结构，并利用该结构进行了基于结构的进化分析。该研究首次包含了分别代表生物界三界（真细菌、古细菌和真核生物）的生物体的色氨酰和酪氨酰tRNA合成酶的晶体结构，因而相比以往的TrpRS进化分析具有较高的可靠性。研究结果揭示了色氨酰tRNA合成酶起源于古细菌的酪氨酰tRNA合成酶，解决了长期以来关于色氨酰tRNA合成酶起源的争论。
该项研究工作得到了国家科技部、国家自然科学基金委、中国科学院及上海市科委的经费支持。（生物谷Bioon.com）
生物谷推荐原始出处：
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.
