%0 Journal Article
%T Structure based hypothesis of a mitochondrial ribosome rescue mechanism
%A Martijn A Huynen
%A Isabel Duarte
%A Zofia M. A. Chrzanowska-Lightowlers
%A Sander B Nabuurs
%J Biology Direct
%D 2012
%I BioMed Central
%R 10.1186/1745-6150-7-14
%X Our model predicts, in agreement with the experimental data, that the 3D structure of mtRF1a allows it to recognize the stop codons UAA and UAG in the A-site of the ribosome. In contrast, we show that mtRF1 likely can only bind the ribosome when the A-site is devoid of mRNA. Furthermore, while mtRF1a will adopt its catalytic conformation, in which it functions as a peptidyl-tRNA hydrolase in the ribosome, only upon binding of a stop codon in the A-site, mtRF1 appears specifically adapted to assume this extended, peptidyl-tRNA hydrolyzing conformation in the absence of mRNA in the A-site.We predict that mtRF1 specifically recognizes ribosomes with an empty A-site and is able to function as a peptidyl-tRNA hydrolase in those situations. Stalled ribosomes with empty A-sites that still contain a tRNA bound to a peptide chain can result from the translation of truncated, stop-codon less mRNAs. We hypothesize that mtRF1 recycles such stalled ribosomes, performing a function that is analogous to that of tmRNA in bacteria.This article was reviewed by Dr. Eugene Koonin, Prof. Knud H. Nierhaus (nominated by Dr. Sarah Teichmann) and Dr. Shamil Sunyaev.
%K Class I release factor
%K mtRF1
%K mtRF1a
%K Mitochondrial genetic code
%K Translation termination
%K Stalled ribosome
%U http://www.biology-direct.com/content/7/1/14/abstract