An unusual mechanism for EF-Tu activation during tmRNA-mediated ribosome rescue
نویسندگان
چکیده
منابع مشابه
GTPase activation of elongation factor EF-Tu by the ribosome during decoding.
We have used single-particle reconstruction in cryo-electron microscopy to determine a structure of the Thermus thermophilus ribosome in which the ternary complex of elongation factor Tu (EF-Tu), tRNA and guanine nucleotide has been trapped on the ribosome using the antibiotic kirromycin. This represents the state in the decoding process just after codon recognition by tRNA and the resulting GT...
متن کاملThe tmRNA system for translational surveillance and ribosome rescue.
The tmRNA system performs translational surveillance and ribosome rescue in all eubacteria and some eukaryotic organelles. This system intervenes when ribosomes read to the 3' end of an mRNA or pause at internal codons with subsequent mRNA cleavage. A complex of alanyl-tmRNA (which functions as a tRNA and mRNA), SmpB protein, and EF-TucGTP binds stalled ribosomes, the nascent polypeptide is tra...
متن کاملtmRNA-mediated trans-translation as the major ribosome rescue system in a bacterial cell
Transfer messenger RNA (tmRNA; also known as 10Sa RNA or SsrA RNA) is a small RNA molecule that is conserved among bacteria. It has structural and functional similarities to tRNA: it has an upper half of the tRNA-like structure, its 5' end is processed by RNase P, it has typical tRNA-specific base modifications, it is aminoacylated with alanine, it binds to EF-Tu after aminoacylation and it ent...
متن کاملStructural Basis for Polyproline-Mediated Ribosome Stalling and Rescue by the Translation Elongation Factor EF-P.
Ribosomes synthesizing proteins containing consecutive proline residues become stalled and require rescue via the action of uniquely modified translation elongation factors, EF-P in bacteria, or archaeal/eukaryotic a/eIF5A. To date, no structures exist of EF-P or eIF5A in complex with translating ribosomes stalled at polyproline stretches, and thus structural insight into how EF-P/eIF5A rescue ...
متن کاملEF-Tu dynamics during pre-translocation complex formation: EF-Tu·GDP exits the ribosome via two different pathways
The G-protein EF-Tu, which undergoes a major conformational change when EF-Tu·GTP is converted to EF-Tu·GDP, forms part of an aminoacyl(aa)-tRNA·EF-Tu·GTP ternary complex (TC) that accelerates the binding of aa-tRNA to the ribosome during peptide elongation. Such binding, placing a portion of EF-Tu in contact with the GTPase Associated Center (GAC), is followed by GTP hydrolysis and Pi release,...
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ژورنال
عنوان ژورنال: RNA
سال: 2013
ISSN: 1355-8382
DOI: 10.1261/rna.042226.113