Linked Life Data

8736541

Source:http://linkedlifedata.com/resource/pubmed/id/8736541

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-2-3
pubmed:abstractText
During anaerobic growth, expression of the fdnGHI and narGHJI operons of Escherichia coli is induced by the NarL protein in response to nitrate. The fdnG operon control region contains four NarL-binding sites (termed NarL heptamers) between positions -70 and -130. The two central NarL heptamers of fdnG are arranged as an inverted repeat and are essential for regulation by NarL. We used mutational analysis of these central heptamers to investigate the precise sequence requirements for NarL-dependent induction. Mutations were examined for their effects on NarL-dependent expression in vivo. Substitutions at position 1 of either heptamer had the strongest effect whereas substitutions at position 7 had the weakest effect. For some positions, alterations in both heptamers had a stronger effect than either of the single changes. The 2 bp spacing between these NarL heptamers was also important for normal nitrate induction. The narG operon control region has at least eight NarL heptamers arranged in two groups. Previous work has shown that nucleotide substitutions in two of these heptamers, centred at positions -195 and -89, severely reduce nitrate induction of narG operon expression in vivo and significantly interfere with NarL-DNA interactions in vitro. Substitutions in heptamers -185 and -101 affected narG operon induction only when the concentration of phospho-NarL was low (during growth in the presence of nitrite). Changes in each of the other four NarL heptamers studied had little or no effect on nitrate or nitrite induction of narG operon expression or on NarL-DNA interactions in vitro.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
621-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Analysis of nitrate regulatory protein NarL-binding sites in the fdnG and narG operon control regions of Escherichia coli K-12.
pubmed:affiliation
Section of Microbiology, Cornell University, Ithaca, New York 14853-8101, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.