5j4d
From Proteopedia
E. coli release factor 1 bound to the 70S ribosome in response to a pseudouridylated stop codon
Structural highlights
FunctionRL2_THET2 One of the primary rRNA binding proteins. Required for association of the 30S and 50S subunits to form the 70S ribosome, for tRNA binding and peptide bond formation. It has been suggested to have peptidyltransferase activity; this is somewhat controversial. Makes several contacts with the 16S rRNA in the 70S ribosome (By similarity). Publication Abstract from PubMedPseudouridylation of messenger RNA emerges as an abundant modification involved in gene expression regulation. Pseudouridylation of stop codons in eukaryotic and bacterial cells results in stop-codon read through. The structural mechanism of this phenomenon is not known. Here we present a 3.1-A crystal structure of Escherichia coli release factor 1 (RF1) bound to the 70S ribosome in response to the PsiAA codon. The structure reveals that recognition of a modified stop codon does not differ from that of a canonical stop codon. Our in vitro biochemical results support this finding by yielding nearly identical rates for peptide release from E. coli ribosomes programmed with pseudouridylated and canonical stop codons. The crystal structure also brings insight into E. coli RF1-specific interactions and suggests involvement of L27 in bacterial translation termination. Our results are consistent with a mechanism in which read through of a pseudouridylated stop codon in bacteria results from increased decoding by near-cognate tRNAs (miscoding) rather than from decreased efficiency of termination. Structural Basis for Translation Termination on a Pseudouridylated Stop Codon.,Svidritskiy E, Madireddy R, Korostelev AA J Mol Biol. 2016 May 22;428(10 Pt B):2228-36. doi: 10.1016/j.jmb.2016.04.018., Epub 2016 Apr 20. PMID:27107638[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found See AlsoReferences
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