EF-G Activation by Phosphate Analogs.
EF-G Activation by Phosphate Analogs.
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DOI：
10.1016/j.jmb.2016.03.032
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发表时间：
2016-05-22
影响因子：
5.6
通讯作者：
Ermolenko DN
中科院分区：
文献类型：
--
作者：
Salsi E;Farah E;Ermolenko DN
EF-G is a universally conserved translational GTPase that promotes the translocation of tRNA and mRNA through the ribosome. EF-G binds to the ribosome in a GTP-bound form and subsequently catalyzes GTP hydrolysis. The contribution of the ribosome-stimulated GTP hydrolysis by EF-G to tRNA/mRNA translocation remains debated. Here, we show that while EF-G•GDP does not stably bind to the ribosome and induce translocation, EFG• GDP in complex with phosphate group analogues BeF3− and AlF4− promotes the translocation of tRNA and mRNA. Furthermore, the rates of mRNA translocation induced by EF-G in the presence of GTP and a non-hydrolysable analogue of GTP, GDP•BeF3−are similar. Our results are consistent with the model suggesting that GTP hydrolysis is not directly coupled to mRNA/tRNA translocation. Hence, GTP binding is required to induce the activated, translocation-competent conformation of EF-G while GTP hydrolysis triggers EF-G release from the ribosome.
