3izq
From Proteopedia
Structure of the Dom34-Hbs1-GDPNP complex bound to a translating ribosome
Structural highlights
FunctionDOM34_YEAST Involved in protein translation. Together with HBS1, may function in recognizing stalled ribosomes and triggering endonucleolytic cleavage of the mRNA, a mechanism to release non-functional ribosomes and degrade damaged mRNAs. The complex formed by DOM34 and HBS1 has ribonuclease activity towards double-stranded RNA substrates, but does not cleave single-stranded RNA. Acts as endonuclease; has no exonuclease activity. Increases the affinity of HBS1 for GTP, but nor for GDP. Promotes G1 progression and differentiation and is involved in mitotic and meiotic cell divisions.[1] [2] [3] Publication Abstract from PubMedNo-go decay (NGD) is a mRNA quality-control mechanism in eukaryotic cells that leads to degradation of mRNAs stalled during translational elongation. The key factors triggering NGD are Dom34 and Hbs1. We used cryo-EM to visualize NGD intermediates resulting from binding of the Dom34-Hbs1 complex to stalled ribosomes. At subnanometer resolution, all domains of Dom34 and Hbs1 were identified, allowing the docking of crystal structures and homology models. Moreover, the close structural similarity of Dom34 and Hbs1 to eukaryotic release factors (eRFs) enabled us to propose a model for the ribosome-bound eRF1-eRF3 complex. Collectively, our data provide structural insights into how stalled mRNA is recognized on the ribosome and how the eRF complex can simultaneously recognize stop codons and catalyze peptide release. Structure of the no-go mRNA decay complex Dom34-Hbs1 bound to a stalled 80S ribosome.,Becker T, Armache JP, Jarasch A, Anger AM, Villa E, Sieber H, Motaal BA, Mielke T, Berninghausen O, Beckmann R Nat Struct Mol Biol. 2011 Jun;18(6):715-20. Epub 2011 May 29. PMID:21623367[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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