Publication details
Cryo-EM ensemble captures EF-G mediated ribosomal translocation in action
| Authors | |
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| Year of publication | 2021 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | During protein synthesis, transfer RNAs (tRNAs) and messenger RNA (mRNA) codons are translocated within the ribosome from the A to P to E sites, respectively. Translocation of tRNAs anticodons and mRNA along the small ribosomal 30S subunit is catalyzed by a conserved GTPase, elongation factor G(EF-G) in bacteria. The structural mechanism how the ribosome and EF-G maintain the open reading frame has not been visualized because the rapid GTP hydrolysis step has prevented the capture of authentic EF-G bound structural intermediates. Here, we present our single particle cryo-EM study aimed at characterizing translocation without using EF-G mutations or antibiotics. We report newly described intermediate structural state, which visualized the transition of two tRNAs from the A and P to P and E sites during translocation. The structure visualizes how nearly rigid EF-G rectifies inherent and spontaneous ribosomal dynamics into tRNA and mRNA translocation. This work therefore uncovers a missing link in the understanding of the synchronous movement of tRNAs and mRNA during translation elongation. |
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