Linked Life Data

8345523

Source:http://linkedlifedata.com/resource/pubmed/id/8345523

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-9-9
pubmed:abstractText
The aspartate receptor is a transmembrane-signalling protein that mediates chemotaxis behaviour in bacteria. Aspartate receptors in Salmonella typhimurium and Escherichia coli exist as dimers of two subunits in the presence as well as in the absence of aspartate. We have previously reported the three-dimensional structures of the external ligand-binding domain of the S. typhimurium aspartate receptor with and without bound aspartate. The external or periplasmic region of the aspartate receptor is a dimer of four-alpha-helical bundle subunits; a single aspartate molecule binds to one of two sites residing at the subunit interface, increasing the affinity of the subunits for one another. Here we report the results of a detailed analysis of the aspartate receptor ligand-binding domain structure (residues 25 to 188). The dimer interface between the twofold related subunits consists primarily of contacts mediated by the side-chains of the N-terminal helix of each four-alpha-helical bundle subunit. The N-terminal helices pack approximately 20 degrees from parallel as an approximate coiled-coil super-secondary structure. We have refined aspartate receptor ligand-binding domain structures in the presence and in the absence of a bound aromatic compound, 1,10-phenanthroline, to 2.2 A and 2.3 A resolution, respectively, as well as crystal structures in the presence of specifically bound Au(I), Hg(II) and Pt(IV) complex ions at 2.4 A, 3.0 A and 3.3 A resolution, respectively. The possible biological relevance of the aromatic ligand-binding site and the metal ion-binding sites is discussed. The dimer of four-alpha-helical bundle subunits composing the periplasmic region of the S. typhimurium aspartate receptor provides a basis for understanding the results of mutational analyses performed on related chemotaxis transmembrane receptors. The crystal structure analysis provides an explanation for the way in which mutations in the E. coli aspartate receptor affect its binding to the periplasmic maltose-binding protein and how mutations in the more distantly related E. coli Trg chemotaxis receptor affect its binding to the periplasmic ribose and glucose-galactose binding proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Aspartic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Gold, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Mercury, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments, http://linkedlifedata.com/resource/pubmed/chemical/Phenanthrolines, http://linkedlifedata.com/resource/pubmed/chemical/Platinum, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Amino Acid, http://linkedlifedata.com/resource/pubmed/chemical/Trg protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/aspartic acid receptor
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
232
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
555-73
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Refined structures of the ligand-binding domain of the aspartate receptor from Salmonella typhimurium.
pubmed:affiliation
Department of Chemistry, University of California, Berkeley 94720.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't