Linked Life Data

9398522

Source:http://linkedlifedata.com/resource/pubmed/id/9398522

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-1-14
pubmed:abstractText
The Escherichia coli nucleoid protein, H-NS, functions as a global regulator for expression of a wide variety of genes. We recently analyzed the structure-function relationship of H-NS with special reference to the domains responsible for transcriptional repression and DNA-binding, respectively. However, identification of the presumed dimerization domain of H-NS and its functional significance was elusive. To address this particular issue, we first examined a set of N-terminally or C-terminally truncated forms of H-NS, in terms of their so-called dominant-negative effect on the in vivo function of the wild-type H-NS. The results showed that certain truncated forms exhibit such a dominant-negative effect, but others did not. As judged by the results of the dominant-negative effect, it was assumed that a relatively central portion of H-NS extending from residues 21 to 63 is involved in dimerization. This was confirmed by an in vitro chemical cross-linking analysis and a gel filtration analysis with these truncated forms of H-NS. Furthermore, the use of the dominant-negative phenotype, caused by a truncated form of H-NS (named N91), allowed us to isolate a missense mutant, which was expected to be specifically defective in dimerization. This mutant had an amino acid substitution at position 30 (Leu30 to Pro) in N91 consisting of the N-terminal 91 amino acids of H-NS. This mutant was indeed defective in the in vitro ability to form a heterodimer with the wild-type H-NS. When this particular single amino acid substitution was introduced into the full-length H-NS, the resultant H-NS mutant had lost the ability to form dimers in vitro and to function as a transcriptional repressor. These findings collectively provided us with evidence that the ability of H-NS to form a dimer is crucial for H-NS to function as a transcriptional repressor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1997 Academic Press Limited.
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
145-51
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9398522-Amino Acid Sequence, pubmed-meshheading:9398522-Bacterial Proteins, pubmed-meshheading:9398522-Blotting, Western, pubmed-meshheading:9398522-Cross-Linking Reagents, pubmed-meshheading:9398522-DNA, Bacterial, pubmed-meshheading:9398522-DNA-Binding Proteins, pubmed-meshheading:9398522-Dimerization, pubmed-meshheading:9398522-Dimethyl Suberimidate, pubmed-meshheading:9398522-Escherichia coli, pubmed-meshheading:9398522-Gene Expression Regulation, Bacterial, pubmed-meshheading:9398522-Lac Operon, pubmed-meshheading:9398522-Molecular Sequence Data, pubmed-meshheading:9398522-Mutagenesis, Site-Directed, pubmed-meshheading:9398522-Plasmids, pubmed-meshheading:9398522-Repressor Proteins, pubmed-meshheading:9398522-Sequence Deletion, pubmed-meshheading:9398522-Transcription, Genetic, pubmed-meshheading:9398522-Transfection, pubmed-meshheading:9398522-beta-Galactosidase
pubmed:year
1997
pubmed:articleTitle
Clarification of the dimerization domain and its functional significance for the Escherichia coli nucleoid protein H-NS.
pubmed:affiliation
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya 464, Chikusa-ku, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't