Petersburg Nuclear Physics Institute named by B.P. Konstantinov of NRC "Kurchatov Institute", Gatchina, Leningrad Region, 188300, Russia.
Biochemistry (Mosc). 2020 Nov;85(11):1422-1433. doi: 10.1134/S0006297920110103.
Translational GTPases (trGTPases) belong to the family of G proteins and play key roles at all stages of protein biosynthesis on the ribosome. Unidirectional and cyclic functioning of G proteins is ensured by their ability to switch between the active and inactive states due to GTP hydrolysis accelerated by the auxiliary GTPase-activating proteins. Although trGTPases interact with the ribosomes in different conformational states, they bind to the same conserved region, which, unlike in classical GTPase-activating proteins, is represented by ribosomal RNA. The resulting catalytic sites have almost identical structure in all elongation factors suggesting a common mechanism of GTP hydrolysis. However, fine details of the activated state formation and significantly different rates of GTP hydrolysis indicate the existence of distinctive features upon GTP hydrolysis catalyzed by the different factors. Here, we present a contemporary view on the mechanism of GTPase activation and GTP hydrolysis by the elongation factors EF-Tu, EF-G, and SelB based on the analysis of structural, biochemical, and bioinformatics data.
翻译转位 GTP 酶（trGTPases）属于 G 蛋白家族，在核糖体上的蛋白质生物合成的所有阶段都发挥着关键作用。G 蛋白的单向和循环功能是通过其由于辅助 GTP 酶激活蛋白加速的 GTP 水解而在活性和非活性状态之间切换的能力来保证的。尽管 trGTPases 在不同的构象状态下与核糖体相互作用，但它们结合到相同的保守区域，与经典的 GTP 酶激活蛋白不同，该区域由核糖体 RNA 代表。在所有伸长因子中，形成的催化位点在结构上几乎相同，这表明在 GTP 水解过程中存在共同的机制。然而，激活状态形成的细微差别和 GTP 水解的速率明显不同表明，不同因素催化的 GTP 水解存在独特的特征。在这里，我们根据结构、生化和生物信息学数据的分析，提出了基于转位 GTP 酶（trGTPases）的伸长因子 EF-Tu、EF-G 和 SelB 的 GTP 酶激活和 GTP 水解机制的现代观点。
