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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
1976-9-25
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pubmed:abstractText |
1. The effect of elongation factor 2 (EF 2) and of adenosine diphosphate-ribosylated elongation factor 2 (ADP-ribosyl-EF 2) on the shift of endogenous peptidyl-tRNA from the A to the P site of rat liver ribosomes (measured by the peptidyl-puromycin reaction) and on the release of deacylated tRNA (measured by aminoacylation) was investigated. 2. Limiting amounts of EF2, pre-bound or added to ribosomes, catalyse the shift of peptidyl-tRNA in the presence of GPT; when the enzyme is added in substrate amounts GMP-P(CH2)P [guanosine (beta, gamma-methylene)triphosphate] can partially replace GTP. ADP-ribosyl-EF 2 has no effect on the shift of peptidyl-tRNA when present in catalytic amounts, but becomes almost as effective as EF 2 when added in substrate amounts together with GTP; GMP-P(CH2)P cannot replace GTP. 3. The release of deacylated tRNA is induced only by substrate amounts of added EF 2 and also occurs in the absence of guanine nucleotides. In this reaction ADP-ribosyl-EF 2 is only 25% as effective as EF 2 in the absence of added nucleotide, but becomes 60-80% as effective in the presence of GTP or GMP-P(CH2)P. 4. The results obtained on protein-synthesizing systems are consistent with the hypothesis that ADP-ribosyl-EF 2 can operate a single round of translocation followed by binding of aminoacyl-tRNA and peptide-bond formation. 5. From the data obtained with the native enzyme it is concluded that the two moments of translocation require different conditions of interaction of EF 2 with ribosomes; it is suggested that the shift of peptidyl-tRNA is catalysed by EF 2 pre-bound to ribosomes, and that the release of tRNA is induced by a second molecule of interacting EF 2. The hydrolysis of GTP would be required for the release of pre-bound EF 2 from ribosomes. 5. The inhibition of the utilization of limiting amounts of EF 2 on ADP-ribosylation is very likely the consequence of a concomitant decrease in the rate of association and dissociation of the enzyme from ribosomes.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-1112785,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-13523068,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-14907713,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-164179,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4296678,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4297784,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4297868,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4303479,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4312031,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4314910,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4327727,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4343622,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4427385,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4448421,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4562740,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4571227,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4582381,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4587121,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4605331,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4622610,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4683490,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4718780,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4723234,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4780693,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4872143,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4884686,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4897025,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4909495,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4918149,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-4934881,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5014445,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5075290,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5266171,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5472364,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5545093,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5656804,
http://linkedlifedata.com/resource/pubmed/commentcorrection/182140-5696502
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0264-6021
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
156
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
15-23
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:182140-Adenosine Diphosphate Sugars,
pubmed-meshheading:182140-Animals,
pubmed-meshheading:182140-Diphtheria Toxin,
pubmed-meshheading:182140-Guanosine Triphosphate,
pubmed-meshheading:182140-Liver,
pubmed-meshheading:182140-NAD,
pubmed-meshheading:182140-Nucleoside Diphosphate Sugars,
pubmed-meshheading:182140-Peptide Chain Elongation, Translational,
pubmed-meshheading:182140-Peptide Elongation Factors,
pubmed-meshheading:182140-Puromycin,
pubmed-meshheading:182140-RNA, Transfer,
pubmed-meshheading:182140-Rats,
pubmed-meshheading:182140-Ribosomal Proteins,
pubmed-meshheading:182140-Ribosomes
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pubmed:year |
1976
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pubmed:articleTitle |
Effect of elongation factor 2 and of adenosine diphosphate-ribosylated elongation factor 2 on translocation.
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pubmed:publicationType |
Journal Article,
In Vitro
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