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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
23
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pubmed:dateCreated |
1984-1-27
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pubmed:abstractText |
The interaction of the Escherichia coli elongation factor Tu guanosine tetraphosphate complex (EF-Tu ppGpp) with aminoacyl-tRNAs(aa-tRNA) was reinvestigated by gel filtration and hydrolysis protection experiments. These experiments show that EF-Tu X ppGpp like EF-Tu X GDP (Pingoud, A., Block, W., Wittinghofer, A., Wolf, H. & Fischer, E. (1982) J. Biol. Chem. 257, 11261-11267) forms a fairly stable complex with Phe-tRNAPhe, KAss being 0.6 X 10(5) M-1 at 25 degrees C. The binding of the EF-Tu X ppGpp X aa-tRNA complex to programmed ribosomes was investigated by a centrifugation technique. It is shown that this complex is bound codon-specific with KAss = 3 X 10(7) M-1 at 0 degrees C and that it stimulates peptidyl transfer. A numerical estimation of the intracellular concentration of EF-Tu X GTP X aa-tRNA and EF-Tu X ppGpp X aa-tRNA during normal growth and under the stringent response indicates that ppGpp accumulation does affect the EF-Tu X GTP X aa-tRNA concentration but does not lead to major depletion of this pool. Furthermore, due to the higher affinity of EF-Tu X GTP to aa-tRNA and of the ternary complex EF-Tu X GTP X aa-tRNA to the ribosome, EF-Tu X ppGpp X aa-tRNA binding to the ribosome is not significant. According to our measurements and calculations, therefore, a direct participation of EF-Tu in slowing down the rate of protein biosynthesis and improving its accuracy during amino acid starvation is not obvious.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Tetraphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Macromolecular Substances,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Elongation Factor Tu,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Elongation Factors,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Transfer, Amino Acyl,
http://linkedlifedata.com/resource/pubmed/chemical/tRNA, phenylalanine-
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
10
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pubmed:volume |
258
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
14200-5
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:6358217-Escherichia coli,
pubmed-meshheading:6358217-Guanosine Tetraphosphate,
pubmed-meshheading:6358217-Guanosine Triphosphate,
pubmed-meshheading:6358217-Macromolecular Substances,
pubmed-meshheading:6358217-Peptide Elongation Factor Tu,
pubmed-meshheading:6358217-Peptide Elongation Factors,
pubmed-meshheading:6358217-RNA, Transfer, Amino Acyl,
pubmed-meshheading:6358217-Ribosomes
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pubmed:year |
1983
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pubmed:articleTitle |
The elongation factor Tu from Escherichia coli, aminoacyl-tRNA, and guanosine tetraphosphate form a ternary complex which is bound by programmed ribosomes.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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