Linked Life Data

6374157

Source:http://linkedlifedata.com/resource/pubmed/id/6374157

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-7-12
pubmed:abstractText
A mutation in the structural gene for threonine deaminase, ilvA538 , results in lower than normal levels of the isoleucyl, valyl- and leucyl-tRNA synthetases. Moreover, this regulatory mutation decreases the level of expression of the ilv biosynthetic operons and renders their expression non-responsive to limitations of the branched-chain amino acids. In this paper, we present in vitro evidence for the inhibition of isoleucyl- and valyl-tRNA synthetase activity by threonine deaminase and 2-ketobutyrate, the product of the threonine deaminase reaction, through the formation of a high molecular weight complex of the three molecules. Based on these results, we propose a model to explain the regulation of the isoleucyl- and valyt -tRNA synthetases in which transient inhibition of the synthetase enzyme activities by threonine deaminase and 2-ketobutyrate increases the expression of ileS and valS , the structural genes for isoleucyl- and valyt -tRNA synthetase, respectively. Further, the results suggest that the hyperattenuated expression of the ilv biosynthetic operons is due to an increased rate of complex formation of valyl and isoleucyl-tRNA synthetases and the altered form of threonine deaminase of the ilvA538 mutant strain.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
175
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-55
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Synthesis of the isoleucyl- and valyl-tRNA synthetases and the isoleucine-valine biosynthetic enzymes in a threonine deaminase regulatory mutant of Escherichia coli K-12.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.