Linked Life Data

8142359

Source:http://linkedlifedata.com/resource/pubmed/id/8142359

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1994-5-2
pubmed:abstractText
To explore the roles of three aspartate residues, Asp88, Asp130, and Asp274, found in the proposed inducer binding site of lac repressor [Sams, C. F., Vyas, N. K., Quiocho, F. A., & Matthews, K. S. (1984) Nature 310, 429-430], each site was substituted with alanine, glutamate, lysine, or asparagine by site-specific mutagenesis. The mutations at the Asp88 site resulted in a 5-13-fold decrease in inducer binding affinity, largely due to an increase in the inducer dissociation rate constants for these mutants. In addition, the mutant proteins Asp88-->Ala and Asp88-->Lys exhibited altered allosteric behavior for inducer binding. These data conflict with the original hypothesis placing Asp88 in the inducer binding site, but are in agreement with a recent model that places this amino acid close to the subunit interface involved in cooperativity associated with inducer binding [Nichols, J. C., Vyas, N. K., Quiocho, F. A., & Matthews, K. S. (1993) J. Biol. Chem. 268, 17602-17612; Chen, J., & Matthews, K. S. (1992) J. Biol. Chem. 267, 13843-13850]. Substitution at Asp130 did not alter the inducer binding affinity nor other binding activities. Thus, this amino acid is not crucial in the binding to beta-substituted monosaccharides or in protein function. In stark contrast, all mutant proteins with substitutions at the Asp274 site exhibited no detectable inducer binding. With the exception of Asp274-->Lys, the structures of these mutant proteins appear to be similar to wild-type. The data demonstrate that Asp274 plays a crucial role in inducer binding of this transcriptional regulator.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3607-16
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8142359-Allosteric Regulation, pubmed-meshheading:8142359-Antibodies, Monoclonal, pubmed-meshheading:8142359-Aspartic Acid, pubmed-meshheading:8142359-Binding Sites, pubmed-meshheading:8142359-Chromatography, Gel, pubmed-meshheading:8142359-Circular Dichroism, pubmed-meshheading:8142359-Galactosides, pubmed-meshheading:8142359-Isopropyl Thiogalactoside, pubmed-meshheading:8142359-Macromolecular Substances, pubmed-meshheading:8142359-Models, Molecular, pubmed-meshheading:8142359-Molecular Structure, pubmed-meshheading:8142359-Mutagenesis, Site-Directed, pubmed-meshheading:8142359-Protein Structure, Secondary, pubmed-meshheading:8142359-Repressor Proteins, pubmed-meshheading:8142359-Spectrometry, Fluorescence, pubmed-meshheading:8142359-Structure-Activity Relationship, pubmed-meshheading:8142359-Trypsin
pubmed:year
1994
pubmed:articleTitle
Identification and characterization of aspartate residues that play key roles in the allosteric regulation of a transcription factor: aspartate 274 is essential for inducer binding in lac repressor.
pubmed:affiliation
Department of Biochemistry & Cell Biology, Rice University, Houston, Texas 77251.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't