Linked Life Data

6348473

Source:http://linkedlifedata.com/resource/pubmed/id/6348473

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1983-9-23
pubmed:abstractText
Derivatives of isogenic stringent (relA+) and relaxed (relA) strains of Escherichia coli were compared in respect of rates of the dissociation of peptidyl-tRNA from ribosomes during protein synthesis. The derivatives both contained a mutant pth gene which rendered temperature-sensitive their peptidyl-tRNA hydrolase (E.C. 3.1.1.29) activities. After shifting from permissive 30 degrees C to non-permissive 40 degrees C, dissociated peptidyl-tRNA accumulated and was assayed chemically or by its cytotoxic effects. In unperturbed (except for the temperature shift) cultures the relA strain accumulated peptidyl-tRNA significantly more slowly than did its relA+ isogenic cousin. Both strains responded approximately equally to non-lethal doses of erythromycin or to starvation for amino acids. Both these perturbations enhanced the dissociation and accumulation of peptidyl-tRNA. While growing at 30 degrees C, both strains responded significantly to a nutritional downshift from growth in medium containing glucose plus amino acids to growth in medium containing only amino acids. Taken together the results suggested that different intracellular concentrations of ppGpp in unperturbed cells, attributable to the different relA alleles, could account for the differences in dissociation and accumulation of peptidyl-tRNA. Our observation of a lower rate of dissociation of peptidyl-tRNA in the relA strain, coupled with the reported lower intracellular ppGpp and lower accuracy of protein synthesis, is consistent with the idea that relA strains have less efficient ribosomal editing of erroneous peptidyl-tRNA.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
190
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
215-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Tests of the ribosome editor hypothesis. II. Relaxed (relA) and stringent (relA+) E. coli differ in rates of dissociation of peptidyl-tRNA from ribosomes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.