| Structural highlights
Function
RS5_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 PubMed
Translocation 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 Also
References
- ↑ Lomakin IB, Steitz TA. The initiation of mammalian protein synthesis and mRNA scanning mechanism. Nature. 2013 Jul 21. doi: 10.1038/nature12355. PMID:23873042 doi:10.1038/nature12355
- ↑ Muhs M, Hilal T, Mielke T, Skabkin MA, Sanbonmatsu KY, Pestova TV, Spahn CM. Cryo-EM of Ribosomal 80S Complexes with Termination Factors Reveals the Translocated Cricket Paralysis Virus IRES. Mol Cell. 2015 Feb 5;57(3):422-432. doi: 10.1016/j.molcel.2014.12.016. Epub 2015 , Jan 15. PMID:25601755 doi:http://dx.doi.org/10.1016/j.molcel.2014.12.016
- ↑ Shao S, Murray J, Brown A, Taunton J, Ramakrishnan V, Hegde RS. Decoding Mammalian Ribosome-mRNA States by Translational GTPase Complexes. Cell. 2016 Nov 17;167(5):1229-1240.e15. doi: 10.1016/j.cell.2016.10.046. PMID:27863242 doi:http://dx.doi.org/10.1016/j.cell.2016.10.046
- ↑ Flis J, Holm M, Rundlet EJ, Loerke J, Hilal T, Dabrowski M, Burger J, Mielke T, Blanchard SC, Spahn CMT, Budkevich TV. tRNA Translocation by the Eukaryotic 80S Ribosome and the Impact of GTP Hydrolysis. Cell Rep. 2018 Dec 4;25(10):2676-2688.e7. doi: 10.1016/j.celrep.2018.11.040. PMID:30517857 doi:http://dx.doi.org/10.1016/j.celrep.2018.11.040
- ↑ Flis J, Holm M, Rundlet EJ, Loerke J, Hilal T, Dabrowski M, Burger J, Mielke T, Blanchard SC, Spahn CMT, Budkevich TV. tRNA Translocation by the Eukaryotic 80S Ribosome and the Impact of GTP Hydrolysis. Cell Rep. 2018 Dec 4;25(10):2676-2688.e7. doi: 10.1016/j.celrep.2018.11.040. PMID:30517857 doi:http://dx.doi.org/10.1016/j.celrep.2018.11.040
|
