1u8t
From Proteopedia
Crystal structure of CheY D13K Y106W alone and in complex with a FliM peptide
Structural highlights
Function[CHEY_ECOLI] Involved in the transmission of sensory signals from the chemoreceptors to the flagellar motors. In its active (phosphorylated or acetylated) form, CheY exhibits enhanced binding to a switch component, FliM, at the flagellar motor which induces a change from counterclockwise to clockwise flagellar rotation. Overexpression of CheY in association with MotA and MotB improves motility of a ycgR disruption, suggesting there is an interaction (direct or indirect) between the c-di-GMP-binding flagellar brake protein and the flagellar stator.[1] [FLIM_ECOLI] FliM is one of three proteins (FliG, FliN, FliM) that forms the rotor-mounted switch complex (C ring), located at the base of the basal body. This complex interacts with the CheY and CheZ chemotaxis proteins, in addition to contacting components of the motor that determine the direction of flagellar rotation. 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 PubMedCheY is a member of the response regulator protein superfamily that controls the chemotactic swimming response of motile bacteria. The CheY double mutant D13K Y106W (CheY**) is resistant to phosphorylation, yet is a highly effective mimic of phosphorylated CheY in vivo and in vitro. The conformational attributes of this protein that enable it to signal in a phosphorylation-independent manner are unknown. We have solved the crystal structure of selenomethionine-substituted CheY** in the presence of its target, a peptide (FliM16) derived from the flagellar motor switch, FliM, to 1.5A resolution with an R-factor of 19.6%. The asymmetric unit contains four CheY** molecules, two with FliM16 bound, and two without. The two CheY** molecules in the asymmetric unit that are bound to FliM16 adopt a conformation similar to BeF3- -activated wild-type CheY, and also bind FliM16 in a nearly identical manner. The CheY** molecules that do not bind FliM16 are found in a conformation similar to unphosphorylated wild-type CheY, suggesting that the active phenotype of this mutant is enabled by a facile interconversion between the active and inactive conformations. Finally, we propose a ligand-binding model for CheY and CheY**, in which Ile95 changes conformation in a Tyr/Trp106-dependent manner to accommodate FliM. Structure of the constitutively active double mutant CheYD13K Y106W alone and in complex with a FliM peptide.,Dyer CM, Quillin ML, Campos A, Lu J, McEvoy MM, Hausrath AC, Westbrook EM, Matsumura P, Matthews BW, Dahlquist FW J Mol Biol. 2004 Sep 24;342(4):1325-35. PMID:15351654[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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