Linked Life Data

3057628

Source:http://linkedlifedata.com/resource/pubmed/id/3057628

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4883
pubmed:dateCreated
1989-1-4
pubmed:abstractText
D-galactose-binding (or chemoreceptor) protein of Escherichia coli serves as an initial component for both chemotaxis towards galactose and glucose and high-affinity active transport of the two sugars. Well-refined x-ray structures of the liganded forms of the wild-type and a mutant protein isolated from a strain defective in chemotaxis but fully competent in transport have provided a molecular view of the sugar-binding site and of a site for interacting with the Trg transmembrane signal transducer. The geometry of the sugar-binding site, located in the cleft between the two lobes of the bilobate protein, is novel in that it is designed for tight binding and sequestering of either the alpha or beta anomer of the D-stereoisomer of the 4-epimers galactose and glucose. Binding specificity and affinity are conferred primarily by polar planar side-chain residues that form intricate networks of cooperative and bidentate hydrogen bonds with the sugar substrates, and secondarily by aromatic residues that sandwich the pyranose ring. Each of the pairs of anomeric hydroxyls and epimeric hydroxyls is recognized by a distinct Asp residue. The site for interaction with the transducer is about 18 A from the sugar-binding site. Mutation of Gly74 to Asp at this site, concomitant with considerable changes in the local ordered water structures, contributes to the lack of productive interaction with the transmembrane signal transducer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0036-8075
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
242
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1290-5
pubmed:dateRevised
2007-3-19
pubmed:meshHeading
pubmed-meshheading:3057628-Bacterial Proteins, pubmed-meshheading:3057628-Binding Sites, pubmed-meshheading:3057628-Calcium-Binding Proteins, pubmed-meshheading:3057628-Carrier Proteins, pubmed-meshheading:3057628-Chemotaxis, pubmed-meshheading:3057628-Computer Simulation, pubmed-meshheading:3057628-DNA Mutational Analysis, pubmed-meshheading:3057628-Escherichia coli, pubmed-meshheading:3057628-Galactose, pubmed-meshheading:3057628-Glucose, pubmed-meshheading:3057628-Hydrogen Bonding, pubmed-meshheading:3057628-Models, Molecular, pubmed-meshheading:3057628-Monosaccharide Transport Proteins, pubmed-meshheading:3057628-Periplasmic Binding Proteins, pubmed-meshheading:3057628-Protein Conformation, pubmed-meshheading:3057628-Structure-Activity Relationship, pubmed-meshheading:3057628-X-Ray Diffraction
pubmed:year
1988
pubmed:articleTitle
Sugar and signal-transducer binding sites of the Escherichia coli galactose chemoreceptor protein.
pubmed:affiliation
Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't