6gz3 | pdb_00006gz3
tRNA translocation by the eukaryotic 80S ribosome and the impact of GTP hydrolysis, Translocation-intermediate-POST-1 (TI-POST-1)
Structural highlights
FunctionRS5_RABIT Component of the small ribosomal subunit (PubMed:23873042, PubMed:25601755, PubMed:27863242, PubMed:30517857). The ribosome is a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell (PubMed:23873042, PubMed:25601755, PubMed:27863242, PubMed:30517857). Part of the small subunit (SSU) processome, first precursor of the small eukaryotic ribosomal subunit (PubMed:23873042, PubMed:25601755, PubMed:27863242, PubMed:30517857). During the assembly of the SSU processome in the nucleolus, many ribosome biogenesis factors, an RNA chaperone and ribosomal proteins associate with the nascent pre-rRNA and work in concert to generate RNA folding, modifications, rearrangements and cleavage as well as targeted degradation of pre-ribosomal RNA by the RNA exosome (By similarity).[UniProtKB:P46782][1] [2] [3] [4] Publication Abstract from PubMedTranslocation moves the tRNA2mRNA module directionally through the ribosome during the elongation phase of protein synthesis. Although translocation is known to entail large conformational changes within both the ribosome and tRNA substrates, the orchestrated events that ensure the speed and fidelity of this critical aspect of the protein synthesis mechanism have not been fully elucidated. Here, we present three high-resolution structures of intermediates of translocation on the mammalian ribosome where, in contrast to bacteria, ribosomal complexes containing the translocase eEF2 and the complete tRNA2mRNA module are trapped by the non-hydrolyzable GTP analog GMPPNP. Consistent with the observed structures, single-molecule imaging revealed that GTP hydrolysis principally facilitates rate-limiting, final steps of translocation, which are required for factor dissociation and which are differentially regulated in bacterial and mammalian systems by the rates of deacyl-tRNA dissociation from the E site. tRNA Translocation by the Eukaryotic 80S Ribosome and the Impact of GTP Hydrolysis.,Flis J, Holm M, Rundlet EJ, Loerke J, Hilal T, Dabrowski M, Burger J, Mielke T, Blanchard SC, Spahn CMT, Budkevich TV Cell Rep. 2018 Dec 4;25(10):2676-2688.e7. doi: 10.1016/j.celrep.2018.11.040. PMID:30517857[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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