1D4Z

CRYSTAL STRUCTURE OF CHEY-95IV, A HYPERACTIVE CHEY MUTANT

Summary for 1D4Z

• Entry DOI: 10.2210/pdb1d4z/pdb
• Descriptor: CHEMOTAXIS PROTEIN CHEY, SULFATE ION (3 entities in total)
• Functional Keywords: bacterial chemotaxis, response regulator, signaling protein
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 14255.30

Authors

Schuster, M.,Zhao, R.,Bourret, R.B.,Collins, E.J. (deposition date: 1999-10-06, release date: 1999-10-14, Last modification date: 2024-02-07)

Primary citation

Schuster, M.,Zhao, R.,Bourret, R.B.,Collins, E.J.
Correlated switch binding and signaling in bacterial chemotaxis.
J.Biol.Chem., 275:19752-19758, 2000

PubMed Abstract: In Escherichia coli, swimming behavior is mediated by the phosphorylation state of the response regulator CheY. In its active, phosphorylated form, CheY exhibits enhanced binding to a switch component, FliM, at the flagellar motor, which induces a change from counterclockwise to clockwise flagellar rotation. When Ile(95) of CheY is replaced by a valine, increased clockwise rotation correlates with enhanced binding to FliM. A possible explanation for the hyperactivity of this mutant is that residue 95 affects the conformation of nearby residues that potentially interact with FliM. In order to assess this possibility directly, the crystal structure of CheY95IV was determined. We found that CheY95IV is structurally almost indistinguishable from wild-type CheY. Several other mutants with substitutions at position 95 were characterized to establish the structural requirements for switch binding and clockwise signaling at this position and to investigate a general relationship between the two properties. The various rotational phenotypes of these mutants can be explained solely by the amount of phosphorylated CheY bound to the switch, which was inferred from the phosphorylation properties of the mutant CheY proteins and their binding affinities to FliM. Combined genetic, biochemical, and crystallographic results suggest that residue 95 itself is critical in mediating the surface complementarity between CheY and FliM.

PubMed: 10748173
DOI: 10.1074/jbc.M909908199

Experimental method

X-RAY DIFFRACTION (1.9 Å)