tmRNA regulates synthesis of the ArfA ribosome rescue factor
نویسندگان
چکیده
منابع مشابه
Mechanism of ribosome rescue by ArfA and RF2
ArfA rescues ribosomes stalled on truncated mRNAs by recruiting release factor RF2, which normally binds stop codons to catalyze peptide release. We report two 3.2 Å resolution cryo-EM structures - determined from a single sample - of the 70S ribosome with ArfA•RF2 in the A site. In both states, the ArfA C-terminus occupies the mRNA tunnel downstream of the A site. One state contains a compact ...
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 کاملArfA recognizes the lack of mRNA in the mRNA channel after RF2 binding for ribosome rescue
Although trans-translation mediated by tmRNA-SmpB has long been known as the sole system to relieve bacterial stalled ribosomes, ArfA has recently been identified as an alternative factor for ribosome rescue in Escherichia coli. This process requires hydrolysis of nascent peptidyl-tRNA by RF2, which usually acts as a stop codon-specific peptide release factor. It poses a fascinating question of...
متن کاملtrans-translation-mediated tight regulation of the expression of the alternative ribosome-rescue factor ArfA in Escherichia coli.
Ribosomes translating mRNA without an in-frame stop codon (non-stop mRNA) stall at its 3' end. In eubacteria, such ribosomes are rescued by SsrA-mediated trans-translation. Recently, we have shown that Escherichia coli ArfA (formerly YhdL) also rescues stalled ribosomes by a mechanism distinct from that of trans-translation. Synthetic lethality phenotype of ssrA arfA double mutants suggests tha...
متن کاملStructure of small protein B: the protein component of the tmRNA-SmpB system for ribosome rescue.
Small protein B (SmpB) is an essential component of the highly conserved tmRNA-SmpB system that has the dual function of releasing stalled ribosomes from damaged messenger RNAs and targeting incompletely synthesized protein fragments for degradation. Nuclear magnetic resonance (NMR) analysis of SmpB from Aquifex aeolicus revealed an antiparallel beta-barrel structure, with three helices packed ...
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ژورنال
عنوان ژورنال: Molecular Microbiology
سال: 2011
ISSN: 0950-382X
DOI: 10.1111/j.1365-2958.2011.07638.x