Linked Life Data

2229038

Source:http://linkedlifedata.com/resource/pubmed/id/2229038

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
1990-12-10
pubmed:abstractText
The fnr gene product, FNR, is a global regulator of anaerobic gene expression in Escherichia coli. When E. coli is switched from aerobic to anaerobic growth conditions, cytochrome o (cyoABCDE) and d oxidase (cydAB) genes are repressed and the anaerobic terminal reductase genes, including nitrate (narGHJI), dimethyl sulfoxide/trimethylamine (dmsABC), and fumarate (frdABCD) reductase, are induced. To determine if certain amino acid residues are essential for FNR to function in this regulatory process, site-directed mutations were introduced into the fnr gene. The resulting mutant proteins were assayed in vivo for their ability to either activate dmsA'-'lacZ and frdA'-'lacZ gene expression, or repress expression of a cyoA'-'lacZ gene fusion. The fnr mutants were grouped into four classes. Class I exhibited a severe decrease in the ability to either activate or repress fnr-dependent gene expression. Mutations in four of the five cysteine residues in the FNR protein were in this class. The sole exception was an FNR Cys16----Ser "mutant" that exhibited normal activity. Class II mutations caused a mild reduction in FNR-dependent activation or repression while Class III mutations conferred a modest increase in the ability of the FNR protein to activate gene expression under aerobic conditions (i.e. FNR*). Finally, Class IV mutations lowered the modest aerobic FNR transcriptional activation function proportionally more than the anaerobic FNR activity. These findings identify an essential role for the NH2 terminus of the FNR protein in its various activities in anaerobic gene regulation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
265
pubmed:geneSymbol
fnr
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18733-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Mutations in fnr that alter anaerobic regulation of electron transport-associated genes in Escherichia coli.
pubmed:affiliation
Department of Microbiology and Molecular Genetics, University of California, Los Angeles 90024.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.