Linked Life Data

1619663

Source:http://linkedlifedata.com/resource/pubmed/id/1619663

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-8-4
pubmed:databankReference
pubmed:abstractText
Inducible overexpression of the Escherichia coli gal operon in the absence of the Gal repressor is known as ultrainduction. The requirement of induction can be eliminated by mutation of a new locus, galS, resulting in constitutive and ultrainduced levels of gal expression. Characterization of the galS gene and its product has revealed an isorepressor of the gal regulon. The Gal isorepressor is a protein of 346 amino acid residues whose amino acid sequence and cellular function, as described here, are very similar to that of Gal repressor, encoded by the galR gene. Transcription from different promoters of the gal regulon, galP1, galP2 and mglP, was examined by primer extension and reverse transcription of mRNA isolated from strains containing mutations in galR and/or galS. In strains containing a galS mutation, overexpression of gal message occurred only in the presence of inducer, while mgl message was constitutively derepressed. The galS mutation also constitutively derepressed an mglA::lacZ fusion, demonstrating that GalS is the mgl repressor. A potential operator site in the mgl promoter was identified at a position analogous to OE in gal. Thus, the gal and mgl operons constitute a regulon. Crosstalk, temporal action, induction spectrum or heteromer formation between repressor and isorepressor may help co-ordinate high affinity galactose transport and galactose utilization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
226
pubmed:geneSymbol
galR, galS, mgl
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
69-83
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Isorepressor of the gal regulon in Escherichia coli.
pubmed:affiliation
Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.