Linked Life Data

8634914

Source:http://linkedlifedata.com/resource/pubmed/id/8634914

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-7-9
pubmed:abstractText
Termination of translation in eukaryotes is governed by two polypeptide chain release factors, eRF1 and eRF3 on the ribosome. eRF1 promotes stop-codon-dependent hydrolysis of peptidyl-tRNA, and eRF3 interacts with eRF1 and stimulates eRF1 activity in the presence of GTP. Here, we have demonstrated that eRF3 is a GTP-binding protein endowed with a negligible, if any, intrinsic GTPase activity that is profoundly stimulated by the joint action of eRF1 and the ribosome. Separately, neither eRF1 nor the ribosome display this effect. Thus, eRF3 functions as a GTPase in the quaternary complex with ribosome, eRF1, and GTP. From the in vitro uncoupling of the peptidyl-tRNA and GTP hydrolyses achieved in this work, we conclude that in ribosomes both hydrolytic reactions are mediated by the formation of the ternary eRF1-eRF3-GTP complex. eRF1 and the ribosome form a composite GTPase-activating protein (GAP) as described for other G proteins. A dual role for the revealed GTPase complex is proposed: in " GTP state," it controls the positioning of eRF1 toward stop codon and peptidyl-tRNA, whereas in "GDP state," it promotes release of eRFs from the ribosome. The initiation, elongation, and termination steps of protein synthesis seem to be similar with respect to GTPase cycles.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1355-8382
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
334-41
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Eukaryotic polypeptide chain release factor eRF3 is an eRF1- and ribosome-dependent guanosine triphosphatase.
pubmed:affiliation
Département de Biologie et Génétique du Développement, CNRS URA 256, Université de Rennes 1, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't