1wat | pdb_00001wat
THE THREE-DIMENSIONAL STRUCTURE OF THE LIGAND-BINDING DOMAIN OF A WILD-TYPE BACTERIAL CHEMOTAXIS RECEPTOR
Structural highlights
Function[MCP2_SALTY] Receptor for the attractant L-aspartate and related amino and dicarboxylic acids. Tar mediates taxis away from the repellents cobalt and nickel. Unlike in E.coli tar, it does not mediates maltose taxis. Chemotactic-signal transducers respond to changes in the concentration of attractants and repellents in the environment, transduce a signal from the outside to the inside of the cell, and facilitate sensory adaptation through the variation of the level of methylation. Attractants increase the level of methylation while repellents decrease the level of methylation, the methyl groups are added by the methyltransferase CheR and removed by the methylesterase CheB. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe three-dimensional structures of the ligand-binding domain of the wild-type Salmonella typhimurium aspartate receptor have been determined in the absence (apo) and presence of bound aspartate (complex) and compared to a cross-linked mutant containing a cysteine at position 36 which does not change signaling behavior of the intact receptor. The structures of the wild-type forms were determined in order to assess the effects of cross-linking on the structure and its influence on conformational changes upon ligand binding. As in the case of the cross-linked mutant receptor, the non-cross-linked ligand-binding domain is dimeric and is composed of 4-alpha-helical bundle monomer subunits related by a crystallographic 2-fold axis in the unbound form and by a non-crystallographic axis in the aspartate-bound form. A comparative study between the non-cross-linked and cross-linked structures has led to the following observations: 1) The long N-terminal helices of the individual subunits in the cross-linked structures are bent toward each other to accommodate the disulfide bond. 2) The rest of the subunit conformation is very similar to that of the wild-type. 3) The intersubunit angle of the cross-linked apo structure is larger by about 13 degrees when compared to the wild-type apo structure. 4) The nature and magnitude of the aspartate-induced conformational changes in the non-cross-linked wild-type structures are very similar to those of the cross-linked structures. The three-dimensional structure of the ligand-binding domain of a wild-type bacterial chemotaxis receptor. Structural comparison to the cross-linked mutant forms and conformational changes upon ligand binding.,Yeh JI, Biemann HP, Pandit J, Koshland DE, Kim SH J Biol Chem. 1993 May 5;268(13):9787-92. PMID:8486661[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also
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