Two classes of EF1-family translational GTPases encoded by giant viruses.
Two classes of EF1-family translational GTPases encoded by giant viruses.
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由巨型病毒编码的两类 EF1 家族翻译 GTP 酶。
DOI：
10.1093/nar/gkz296
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发表时间：
2019
影响因子：
14.9
通讯作者：
Hellen,ChristopherUT
中科院分区：
文献类型：
--
作者：
Zinoviev,Alexandra;Kuroha,Kazushige;Pestova,TatyanaV;Hellen,ChristopherUT
巨型病毒具有非常大的双链DNA基因组，并且特别地，它们编码翻译装置的各种组分，包括tRNA、氨酰-tRNA合成酶和翻译因子。在这里，我们专注于病毒翻译GTP酶（trGTP酶）的延伸因子1（EF 1）家族，使用计算和功能的方法来阐明它们的功能。多重序列比对结果表明，这些trGTP酶可分为两类，分别由Mimiviridae和Marseilleviridae的成员表位。第一组中的trGTP酶与GTP结合蛋白1（GTPBP 1）更密切相关，而第二组中的trGTP酶与eEF 1A、eRF 3和Hbs 1更密切相关。利用体外重组技术对代表性的GTPBP 1-like trGTP酶（由水蛭病毒、猫托病毒和鼠病毒编码）进行功能表征，发现它们具有eEF 1A-like活性，并能在翻译延伸过程中将同源aa-tRNA递送到核糖体A位点。相比之下，由马赛病毒和洛桑病毒编码的代表性eEF 1A/eRF 3/Hbs 1样病毒trGTP酶具有eRF 3样终止活性并刺激eRF 1释放肽。我们的分析确定了这些病毒trGTP酶与人类，阿米巴和马赛病毒起源的eRF 1的功能的特定方面。
Giant viruses have extraordinarily large dsDNA genomes, and exceptionally, they encode various components of the translation apparatus, including tRNAs, aminoacyl-tRNA synthetases and translation factors. Here, we focused on the elongation factor 1 (EF1) family of viral translational GTPases (trGTPases), using computational and functional approaches to shed light on their functions. Multiple sequence alignment indicated that these trGTPases clustered into two groups epitomized by members ofMimiviridaeandMarseilleviridae, respectively. trGTPases in the first group were more closely related to GTP-binding protein 1 (GTPBP1), whereas trGTPases in the second group were closer to eEF1A, eRF3 and Hbs1. Functional characterization of representative GTPBP1-like trGTPases (encoded by Hirudovirus, Catovirus and Moumouvirus) usingin vitroreconstitution revealed that they possess eEF1A-like activity and can deliver cognate aa-tRNAs to the ribosomal A site during translation elongation. By contrast, representative eEF1A/eRF3/Hbs1-like viral trGTPases, encoded by Marseillevirus and Lausannevirus, have eRF3-like termination activity and stimulate peptide release by eRF1. Our analysis identified specific aspects of the functioning of these viral trGTPases with eRF1 of human, amoebal and Marseillevirus origin.