Cryo-EM shows stages of initial codon selection on the ribosome by aa-tRNA in ternary complex with GTP and the GTPase-deficient EF-TuH84A
Year: 2018
Type: article
Abstract: The GTPase EF-Tu in ternary complex with GTP and aminoacyl-tRNA (aa-tRNA) promotes rapid and accurate delivery of cognate aa-tRNAs to the ribosomal A site. Here we used cryo-EM to study the molecular origins of the accuracy of ribosome-aided recognition of a cognate ternary complex and the accuracy-amplifying role of the monitoring bases A1492, A1493 and G530 of the 16S rRNA. We used the GTPase-deficient EF-Tu variant H84A with native GTP, rather than non-cleavable GTP analogues, to trap a near-cognate ternary complex in high-resolution ribosomal complexes of varying codon-recognition accuracy. We found that ribosome complexes trapped by GTPase-deficicent ternary complex due to the presence of EF-TuH84A or non-cleavable GTP analogues have very similar structures. We further discuss speed and accuracy of initial aa-tRNA selection in terms of conformational changes of aa-tRNA and stepwise activation of the monitoring bases at the decoding center of the ribosome.
Source: Nucleic Acids Research
DOI: 10.1093/nar/gky346
Authors: Marcus Fislage, Jingji Zhang, Zuben Patrick Brown, Chandra Sekhar Mandava, Suparna Sanyal, Måns Ehrenberg, Joachim Frank
Institutions: Columbia University, Uppsala University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,992
Awards: Structural Analysis of Macromolecular Assemblies, G3210893216, Time-resolved cryo-EM studies of genetic code translation in prokaryotes and eukaryotes, An Integrated Environment for Ribosome Research, Functional and Structural Studies on Ribosomal Stalk Proteins and Translational GTPases, Att förklara proteinsyntesen i mykobakterier med hög effekt för riktad läkemedelsutveckling (Beviljad ansökan överförd från Vinnova med dnr 2013-02072)
OpenAlex ID: W2802665554