Linked Life Data

9000626

Source:http://linkedlifedata.com/resource/pubmed/id/9000626

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1997-2-12
pubmed:databankReference
pubmed:abstractText
The independently folding 63-residue N-terminal DNA-binding domain of the 434 repressor, 434(1-63), contains a buried Arg10-Glu35 salt bridge. A corresponding salt bridge is found in a variety of prokaryotic and eukaryotic DNA-binding proteins with helix-turn-helix motifs. Here, the NMR solution structures of 434(1-63) and the mutant protein 434[R10M](1-63) were determined to investigate the structural role of this salt bridge. Both proteins contain the same type of global fold, with five alpha-helices and a helix-turn-helix motif formed by the helices II and III. The primary structural difference caused by the Arg10 --> Met mutation is a translation of helix I along its axis relative to the helix II-turn-helix III motif. This limited conformational change is paralleled by a 9 kJ M(-1) decrease of the stability of the folded mutant protein in aqueous solution at pH 4.8. It affects the pKa value of Glu19 as well as the population of a hydrogen bond between the backbone amide proton of Asn16 and the side-chain carboxylate group of Glu19. Using the crystal structure of the 434 repressor dimer complexed with the operator DNA as a basis, model building of the DNA complex with the NMR structure of 434[R10M](1-63) shows that Asn16, which is located on the protein surface, makes direct contact with the DNA and indicates that the point mutation Arg10 --> Met should also lead to modifications of the protein-protein contacts in the complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1002-12
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Structural role of a buried salt bridge in the 434 repressor DNA-binding domain.
pubmed:affiliation
Institut für Molekularbiologie und Biophysik, Eidgenössische Technische, Hochschule-Hönggerberg, Zürich, Switzerland.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't