1WAT

THE THREE-DIMENSIONAL STRUCTURE OF THE LIGAND-BINDING DOMAIN OF A WILD-TYPE BACTERIAL CHEMOTAXIS RECEPTOR

Summary for 1WAT

• Entry DOI: 10.2210/pdb1wat/pdb
• Descriptor: ASPARTATE RECEPTOR, ASPARTIC ACID (2 entities in total)
• Functional Keywords: chemotaxis
• Biological source: Salmonella typhimurium
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P02941
• Total number of polymer chains: 2
• Total formula weight: 32865.56

Authors

Kim, S.-H. (deposition date: 1993-03-09, release date: 1994-12-20, Last modification date: 2024-02-14)

Primary citation

Yeh, J.I.,Biemann, H.P.,Pandit, J.,Koshland, D.E.,Kim, S.H.
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.
J.Biol.Chem., 268:9787-9792, 1993

PubMed Abstract: The 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.

PubMed: 8486661

Experimental method

X-RAY DIFFRACTION (3 Å)