4v7b | pdb_00004v7b

Visualization of two tRNAs trapped in transit during EF-G-mediated translocation

Loading... Status: waiting for Mol* initialization Structural highlights 4v7b is a 10 chain structure with sequence from Escherichia coli K-12. This structure supersedes the now removed PDB entries 3j5n and 3j5o. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 5MU, FUA, GDP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RS2_ECOLI Publication Abstract from PubMed During protein synthesis, coupled translocation of messenger RNAs (mRNA) and transfer RNAs (tRNA) through the ribosome takes place following formation of each peptide bond. The reaction is facilitated by large-scale conformational changes within the ribosomal complex and catalyzed by elongtion factor G (EF-G). Previous structural analysis of the interaction of EF-G with the ribosome used either model complexes containing no tRNA or only a single tRNA, or complexes where EF-G was directly bound to ribosomes in the posttranslocational state. Here, we present a multiparticle cryo-EM reconstruction of a translocation intermediate containing two tRNAs trapped in transit, bound in chimeric intrasubunit ap/P and pe/E hybrid states. The downstream ap/P-tRNA is contacted by domain IV of EF-G and P-site elements within the 30S subunit body, whereas the upstream pe/E-tRNA maintains tight interactions with P-site elements of the swiveled 30S head. Remarkably, a tight compaction of the tRNA pair can be seen in this state. The translocational intermediate presented here represents a previously missing link in understanding the mechanism of translocation, revealing that the ribosome uses two distinct molecular ratchets, involving both intra- and intersubunit rotational movements, to drive the synchronous movement of tRNAs and mRNA. Visualization of two transfer RNAs trapped in transit during elongation factor G-mediated translocation.,Ramrath DJ, Lancaster L, Sprink T, Mielke T, Loerke J, Noller HF, Spahn CM Proc Natl Acad Sci U S A. 2013 Dec 24;110(52):20964-9. doi:, 10.1073/pnas.1320387110. Epub 2013 Dec 9. PMID:24324168 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Elongation factor 3D structures

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