Linked Life Data

142769

Source:http://linkedlifedata.com/resource/pubmed/id/142769

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1977-10-31
pubmed:abstractText
Leaky revertants isolated from isoleucine auxotrophs of Serratia marcescens mutant resistant to alpha-aminobutyric acid were previously reported to accumulate leucine in the medium, due to the absence of both feedback inhibition and repression of leucine biosynthesis. Growth of the revertant was accelerated by pyruvate, D(-)-citramalate, citraconate, and alpha-ketobutyrate, but not by threonine. Extracts of the revertant exhibited high activities of pyruvate-dependent coenzyme A liberation from acetyl-coenzyme A, hydration of citraconate, and conversion of citraconate to alpha-ketobutyrate, but showed no threonine-deaminating activity. In the leucine-accumulating revertants the above three activities were not affected by leucine, but in the wild strain and other revertants accumulating no leucine all or one of these activities was controlled by leucine. A leucine auxotroph isolated from the leucine-accumulating revertant showed isoleucine auxotrophy as well. From these data, it is concluded that, in leucine-accumulating revertants, of S. marcescent, isoleucine, is synthesized from alpha-ketobutyrate via citramalate formed from pyruvate annd acetyl-coenzyme A by leucine biosynthetic enzymes, as a result of desensitization of alpha-isopropylmalate synthetase to feedback inhibition.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
95-103
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Pathway for isoleucine formation form pyruvate by leucine biosynthetic enzymes in leucine-accumulating isoleucine revertants of Serratia marcescens.
pubmed:publicationType
Journal Article