3jag

Structure of a mammalian ribosomal termination complex with ABCE1, eRF1(AAQ), and the UAA stop codonStructure of a mammalian ribosomal termination complex with ABCE1, eRF1(AAQ), and the UAA stop codon

3jag, resolution 3.65Å

Structural highlights

3jag is a 10 chain structure with sequence from Oryctolagus cuniculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 3.65Å
Ligands:
Experimental data:	Check
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RL8_RABIT Component of the large ribosomal subunit (PubMed:25601755, PubMed:26245381, PubMed:27863242, PubMed:30517857). The ribosome is a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell (PubMed:25601755, PubMed:26245381, PubMed:27863242, PubMed:30517857).^[1] ^[2] ^[3] ^[4]

Publication Abstract from PubMed

Termination of protein synthesis occurs when a translating ribosome encounters one of three universally conserved stop codons: UAA, UAG or UGA. Release factors recognize stop codons in the ribosomal A-site to mediate release of the nascent chain and recycling of the ribosome. Bacteria decode stop codons using two separate release factors with differing specificities for the second and third bases. By contrast, eukaryotes rely on an evolutionarily unrelated omnipotent release factor (eRF1) to recognize all three stop codons. The molecular basis of eRF1 discrimination for stop codons over sense codons is not known. Here we present cryo-electron microscopy (cryo-EM) structures at 3.5-3.8 A resolution of mammalian ribosomal complexes containing eRF1 interacting with each of the three stop codons in the A-site. Binding of eRF1 flips nucleotide A1825 of 18S ribosomal RNA so that it stacks on the second and third stop codon bases. This configuration pulls the fourth position base into the A-site, where it is stabilized by stacking against G626 of 18S rRNA. Thus, eRF1 exploits two rRNA nucleotides also used during transfer RNA selection to drive messenger RNA compaction. In this compacted mRNA conformation, stop codons are favoured by a hydrogen-bonding network formed between rRNA and essential eRF1 residues that constrains the identity of the bases. These results provide a molecular framework for eukaryotic stop codon recognition and have implications for future studies on the mechanisms of canonical and premature translation termination.

Structural basis for stop codon recognition in eukaryotes.,Brown A, Shao S, Murray J, Hegde RS, Ramakrishnan V Nature. 2015 Aug 27;524(7566):493-6. doi: 10.1038/nature14896. Epub 2015 Aug 5. PMID:26245381^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ 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
↑ Brown A, Shao S, Murray J, Hegde RS, Ramakrishnan V. Structural basis for stop codon recognition in eukaryotes. Nature. 2015 Aug 27;524(7566):493-6. doi: 10.1038/nature14896. Epub 2015 Aug 5. PMID:26245381 doi:http://dx.doi.org/10.1038/nature14896
↑ 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
↑ Brown A, Shao S, Murray J, Hegde RS, Ramakrishnan V. Structural basis for stop codon recognition in eukaryotes. Nature. 2015 Aug 27;524(7566):493-6. doi: 10.1038/nature14896. Epub 2015 Aug 5. PMID:26245381 doi:http://dx.doi.org/10.1038/nature14896

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OCA

[1] 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

[2] Brown A, Shao S, Murray J, Hegde RS, Ramakrishnan V. Structural basis for stop codon recognition in eukaryotes. Nature. 2015 Aug 27;524(7566):493-6. doi: 10.1038/nature14896. Epub 2015 Aug 5. PMID:26245381 doi:http://dx.doi.org/10.1038/nature14896

[3] 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

[4] 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

[5] Brown A, Shao S, Murray J, Hegde RS, Ramakrishnan V. Structural basis for stop codon recognition in eukaryotes. Nature. 2015 Aug 27;524(7566):493-6. doi: 10.1038/nature14896. Epub 2015 Aug 5. PMID:26245381 doi:http://dx.doi.org/10.1038/nature14896

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