Linked Life Data

7040602

Source:http://linkedlifedata.com/resource/pubmed/id/7040602

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-6-21
pubmed:abstractText
The flow of carbon to alpha-acetolactate is Escherichia coli K12 is shown to involve the endogenous pool of alpha-ketobutyrate (alpha-KB). In vivo, the acetohydroxy acid synthase (AHAS) isoenzymes have an affinity for alpha-KB sufficiently high that alpha-acetolactate production is severely limited when alpha K-B is supplied exogenously. The ability of threonine deaminase to make alpha-KB is correlated with the synthesis of the AHAS isoenzymes. Mutations in ilvA that alter the catalytic and allosteric properties of threonine deaminase affect alpha-KB production and the expression of the AHAS isoenzymes in a direct way. The ilv A538 mutation results in a feedback-hypersensitive threonine deaminase ans slow alpha-KB and AHAS production. A spontaneous revertant of an ilvA538 strain expressing a feedback-resistant threonine deaminase produces alpha-KB and AHAS more quickly. A physiological role for the activator (valine) site on threonine deaminase is proposed and valine is shown to increase alpha-KB production in vivo. Valine can thus regulate its own biosynthetic pathway without jeopardizing the production of isoleucine. The physiological implications of the role of alpha-KB in the biosynthesis of acetolactate are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1287
pubmed:author
pubmed:issnType
Print
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19-25
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
A role for threonine deaminase in the regulation of alpha-acetolactate biosynthesis in Escherichia coli K12.
pubmed:publicationType
Journal Article