Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-2-3
pubmed:abstractText
In the human enteropathogen Shigella transcription of virF, the primary regulator of the invasion functions, is strictly temperature-dependent and is antagonistically mediated by H-NS and FIS, which bind to specific sites on the virF promoter. Here we report on the relevance of DNA geometry to the thermoregulation of virF and demonstrate that the virF promoter hosts a major DNA bend halfway between two H-NS sites. The bent region has been mutagenized in vitro to mimic temperature-induced changes of DNA curvature. Functional analysis of curvature mutants and of promoter constructs in which the two H-NS sites are phased-out by a half-helix turn reveals that modifying the spatial relationships between these sites severely affects the interaction of H-NS with the virF promoter, as well as its in vivo and in vitro temperature-dependent activity. The role of promoter curvature as thermosensor is also compatible with the present observation that, with increasing temperature, the virF bending centre moves downstream at a rate having its maximum around the transition temperature, abruptly unmasking a binding site for the transcriptional activator FIS.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
523-37
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
The virF promoter in Shigella: more than just a curved DNA stretch.
pubmed:affiliation
Dip. Biologia Cellulare e dello Sviluppo, University La Sapienza, 00185 Roma, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't