Linked Life Data

14617169

Source:http://linkedlifedata.com/resource/pubmed/id/14617169

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-11-17
pubmed:abstractText
H-NS is an abundant bacterial protein involved in transcriptional silencing of a variety of environmentally responsive genes during growth under non-permissive conditions. We have previously demonstrated a direct role for H-NS in the negative modulation of expression of several genes within the ToxR virulence regulon of Vibrio cholerae. Here we have undertaken extensive mutagenesis of the structural and functional domains of the H-NS protein to determine the contribution of each to the regulation of gene expression. Insertions within, or truncations of, the C-terminal conserved DNA-binding domain prevent repression of toxT and ctx, as expected. Dominant negative experiments demonstrate that V. cholerae H-NS represses gene expression as an oligomeric protein. Hydrophobic coiledcoil interactions have been shown to provide oligomerization capability in other H-NS orthologues. We used site-directed mutagenesis to construct altered V. cholerae H-NS proteins, including an extensive internal deletion within the predicted coiledcoil domain. Remarkably, these proteins were competent to repress gene expression and to form oligomers. Chimeric H-NS proteins, using sequences from both Escherichia coli and V. cholerae H-NS orthologues, revealed that V. cholerae H-NS possesses a second oligomerization domain in the N-terminal 24 amino acids of the protein. Overall, our results suggest DNA binding and protein oligomerization, provided by either the central coiledcoil or N-terminal domain, are required for repression of promoters responsive to H-NS within the ToxR regulon.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
427-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Vibrio cholerae H-NS domain structure and function with respect to transcriptional repression of ToxR regulon genes reveals differences among H-NS family members.
pubmed:affiliation
Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.