Linked Life Data

12511961

Source:http://linkedlifedata.com/resource/pubmed/id/12511961

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6918
pubmed:dateCreated
2003-1-3
pubmed:databankReference
pubmed:abstractText
Termination of protein synthesis occurs when the messenger RNA presents a stop codon in the ribosomal aminoacyl (A) site. Class I release factor proteins (RF1 or RF2) are believed to recognize stop codons via tripeptide motifs, leading to release of the completed polypeptide chain from its covalent attachment to transfer RNA in the ribosomal peptidyl (P) site. Class I RFs possess a conserved GGQ amino-acid motif that is thought to be involved directly in protein-transfer-RNA bond hydrolysis. Crystal structures of bacterial and eukaryotic class I RFs have been determined, but the mechanism of stop codon recognition and peptidyl-tRNA hydrolysis remains unclear. Here we present the structure of the Escherichia coli ribosome in a post-termination complex with RF2, obtained by single-particle cryo-electron microscopy (cryo-EM). Fitting the known 70S and RF2 structures into the electron density map reveals that RF2 adopts a different conformation on the ribosome when compared with the crystal structure of the isolated protein. The amino-terminal helical domain of RF2 contacts the factor-binding site of the ribosome, the 'SPF' loop of the protein is situated close to the mRNA, and the GGQ-containing domain of RF2 interacts with the peptidyl-transferase centre (PTC). By connecting the ribosomal decoding centre with the PTC, RF2 functionally mimics a tRNA molecule in the A site. Translational termination in eukaryotes is likely to be based on a similar mechanism.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
421
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
90-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Structure of the Escherichia coli ribosomal termination complex with release factor 2.
pubmed:affiliation
Department of Biological Sciences, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't