Gene Symbol: cheC
Description: flagellar motor switching and energizing component
Alias: ECK1943, JW1929, cheC2, flaA, flaAII, flaQII
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Sagi Y, Khan S, Eisenbach M. Binding of the chemotaxis response regulator CheY to the isolated, intact switch complex of the bacterial flagellar motor: lack of cooperativity. J Biol Chem. 2003;278:25867-71 pubmed
    ..and Eisenbach, M. (2001) J. Mol. Biol. 312, 699-709), indicates that the chemotactic signal is amplified within the switch, subsequent to the CheY approximately P binding. ..
  2. Clegg D, Koshland D. Identification of a bacterial sensing protein and effects of its elevated expression. J Bacteriol. 1985;162:398-405 pubmed
    The Escherichia coli flaA gene product (also called cheC) plays a crucial role in switching flagellar rotational direction during chemotactic responses...
  3. Sowa Y, Rowe A, Leake M, Yakushi T, Homma M, Ishijima A, et al. Direct observation of steps in rotation of the bacterial flagellar motor. Nature. 2005;437:916-9 pubmed
    ..Backwards steps despite the absence of the flagellar switching protein CheY indicate a small change in free energy per step, similar to that of a single ion transit. ..
  4. Macnab R. How bacteria assemble flagella. Annu Rev Microbiol. 2003;57:77-100 pubmed
    ..Exported substrates diffuse down a narrow channel in the growing structure and assemble at the distal end, often with the help of a capping structure. ..
  5. Sourjik V, Berg H. Binding of the Escherichia coli response regulator CheY to its target measured in vivo by fluorescence resonance energy transfer. Proc Natl Acad Sci U S A. 2002;99:12669-74 pubmed
    ..Using these data, we were able to construct a simple model for the chemotactic pathway and to estimate values of rate constants for several key reactions. ..
  6. Dyer C, Dahlquist F. Switched or not?: the structure of unphosphorylated CheY bound to the N terminus of FliM. J Bacteriol. 2006;188:7354-63 pubmed
    ..Additionally, this structure provides a high-resolution view of an intermediate conformation of a response regulator protein, which had been generally assumed to be two state. ..
  7. Alon U, Camarena L, Surette M, Aguera y Arcas B, Liu Y, Leibler S, et al. Response regulator output in bacterial chemotaxis. EMBO J. 1998;17:4238-48 pubmed
    ..Thus the level of intracellular P-CheY can be estimated from behavior determinations: approximately 30% of the intracellular pool of CheY appears to be phosphorylated in fully adapted wild-type cells. ..
  8. Garza A, Bronstein P, Valdez P, Harris Haller L, Manson M. Extragenic suppression of motA missense mutations of Escherichia coli. J Bacteriol. 1996;178:6116-22 pubmed
  9. Welch M, Oosawa K, Aizawa S, Eisenbach M. Phosphorylation-dependent binding of a signal molecule to the flagellar switch of bacteria. Proc Natl Acad Sci U S A. 1993;90:8787-91 pubmed
    ..This study provides a biochemical demonstration of binding of a signal molecule to the bacterial switch and demonstrates directly that phosphorylation regulates the activity of this molecule. ..

More Information


  1. Marykwas D, Berg H. A mutational analysis of the interaction between FliG and FliM, two components of the flagellar motor of Escherichia coli. J Bacteriol. 1996;178:1289-94 pubmed
    ..This clustering, when compared with results of previous studies, suggests that the FliG-FliM interaction plays a central role in switching. ..
  2. Thomas D, Morgan D, DeRosier D. Rotational symmetry of the C ring and a mechanism for the flagellar rotary motor. Proc Natl Acad Sci U S A. 1999;96:10134-9 pubmed
    ..Movement results from the swapping of stud-bound levers with M ring-bound levers. The model predicts that both the M and C rings rotate in the same direction but at different speeds. ..
  3. Jones C, Macnab R, Okino H, Aizawa S. Stoichiometric analysis of the flagellar hook-(basal-body) complex of Salmonella typhimurium. J Mol Biol. 1990;212:377-87 pubmed
    ..The ring stoichiometries are discussed in light of other information concerning flagellar structure and function. ..
  4. Raha M, Sockett H, Macnab R. Characterization of the fliL gene in the flagellar regulon of Escherichia coli and Salmonella typhimurium. J Bacteriol. 1994;176:2308-11 pubmed
    ..Thus, FliL does not appear to have a major role in flagellar structure or function and is therefore unlikely to be a component of the motor or switch; the effect on motility caused by truncation of the gene is probably an indirect one. ..
  5. Malakooti J, Ely B, Matsumura P. Molecular characterization, nucleotide sequence, and expression of the fliO, fliP, fliQ, and fliR genes of Escherichia coli. J Bacteriol. 1994;176:189-97 pubmed
    ..The FliP protein was homologous to proteins encoded by a DNA sequence upstream of the flaA gene of Rhizobium meliloti, to a gene involved in pathogenicity in Xanthomonas campestris pv...
  6. Manson M. How 34 pegs fit into 26 + 8 holes in the flagellar motor. J Bacteriol. 2007;189:291-3 pubmed
  7. Zhou J, Lloyd S, Blair D. Electrostatic interactions between rotor and stator in the bacterial flagellar motor. Proc Natl Acad Sci U S A. 1998;95:6436-41 pubmed
    ..These results identify a functionally important site of interaction between the rotor and stator and suggest a hypothesis for electrostatic interactions at the rotor-stator interface. ..
  8. Ridgway H, Silverman M, Simon M. Localization of proteins controlling motility and chemotaxis in Escherichia coli. J Bacteriol. 1977;132:657-65 pubmed
    ..Differences in the intracellular locations of the che and mot gene prodcuts presumably reflect the functional attributes of these components. ..
  9. Rajagopala S, Hughes K, Uetz P. Benchmarking yeast two-hybrid systems using the interactions of bacterial motility proteins. Proteomics. 2009;9:5296-302 pubmed publisher
  10. Braun T, Al Mawsawi L, Kojima S, Blair D. Arrangement of core membrane segments in the MotA/MotB proton-channel complex of Escherichia coli. Biochemistry. 2004;43:35-45 pubmed
  11. Saijo Hamano Y, Uchida N, Namba K, Oosawa K. In vitro characterization of FlgB, FlgC, FlgF, FlgG, and FliE, flagellar basal body proteins of Salmonella. J Mol Biol. 2004;339:423-35 pubmed
    ..These results together with other data indicate that all of the ten flagellar axial proteins share structural characteristics and folding dynamics in relation to the mechanism of their self-assembly into the flagellar axial structure. ..
  12. Malakooti J, Komeda Y, Matsumura P. DNA sequence analysis, gene product identification, and localization of flagellar motor components of Escherichia coli. J Bacteriol. 1989;171:2728-34 pubmed
    ..codons (ATG) for motD translation, the first of which overlapped with the termination codon of the upstream gene, flaAII (fliN). The wild-type flaAI gene on the chromosome was replaced with a flaAI gene mutated in vitro...
  13. Passmore S, Meas R, Marykwas D. Analysis of the FliM/FliG motor protein interaction by two-hybrid mutation suppression analysis. Microbiology. 2008;154:714-24 pubmed publisher
    ..These mutations help define a FliG-interaction surface on FliM. Moreover, the pattern of suppression suggests that two distinct sites on FliG interact with FliM, perhaps with two FliM molecules in a dimer per molecule of FliG. ..
  14. Paul K, Blair D. Organization of FliN subunits in the flagellar motor of Escherichia coli. J Bacteriol. 2006;188:2502-11 pubmed
    ..Electron microscopic reconstructions show a bulge at the bottom of the C-ring whose size and shape are a close match for the hypothesized FliN tetramer. ..
  15. Dyer C, Quillin M, Campos A, Lu J, McEvoy M, Hausrath A, et al. Structure of the constitutively active double mutant CheYD13K Y106W alone and in complex with a FliM peptide. J Mol Biol. 2004;342:1325-35 pubmed
    ..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. ..
  16. Grünenfelder B, Gehrig S, Jenal U. Role of the cytoplasmic C terminus of the FliF motor protein in flagellar assembly and rotation. J Bacteriol. 2003;185:1624-33 pubmed
    ..These results provide genetic support for a model in which only a short stretch of amino acids at the immediate C terminus of FliF is required for flagellar assembly through stable interaction with the FliG switch protein. ..
  17. Duke T, Le Novère N, Bray D. Conformational spread in a ring of proteins: a stochastic approach to allostery. J Mol Biol. 2001;308:541-53 pubmed
    ..Conformational spread appears to be a natural extension of the familiar mechanism of allostery: a physically realistic mechanism that should apply widely to many structures built from protein molecules. ..
  18. Marykwas D, Schmidt S, Berg H. Interacting components of the flagellar motor of Escherichia coli revealed by the two-hybrid system in yeast. J Mol Biol. 1996;256:564-76 pubmed
    ..Regions of proteins important for several of these interactions were identified by mutational analysis. The implications for motor assembly and function are discussed. ..
  19. Katayama E, Shiraishi T, Oosawa K, Baba N, Aizawa S. Geometry of the flagellar motor in the cytoplasmic membrane of Salmonella typhimurium as determined by stereo-photogrammetry of quick-freeze deep-etch replica images. J Mol Biol. 1996;255:458-75 pubmed
    ..Various dimensions of the MS ring complex and the C ring projecting from the membrane were determined by digital stereo-photogrammetry, and a three-dimensional model of the total basal structure is presented. ..
  20. Zhou J, Fazzio R, Blair D. Membrane topology of the MotA protein of Escherichia coli. J Mol Biol. 1995;251:237-42 pubmed
    ..These experiments establish that the main features of the suggested model for MotA topology are correct, furnishing a basis for more detailed structure-function studies of the MotA/MotB proton channel...
  21. Reid S, Leake M, Chandler J, Lo C, Armitage J, Berry R. The maximum number of torque-generating units in the flagellar motor of Escherichia coli is at least 11. Proc Natl Acad Sci U S A. 2006;103:8066-71 pubmed
    ..Speed increments at high numbers of units are smaller than those at low numbers, indicating that not all units in a fully induced motor are equivalent. ..
  22. Suzuki H, Yonekura K, Murata K, Hirai T, Oosawa K, Namba K. A structural feature in the central channel of the bacterial flagellar FliF ring complex is implicated in type III protein export. J Struct Biol. 1998;124:104-14 pubmed
    ..This suggests that a domain of FliF partially occupies the central channel to be involved in the export and gate mechanism, and the domain changes its conformation depending on the ionic strength. ..
  23. Garza A, Harris Haller L, Stoebner R, Manson M. Motility protein interactions in the bacterial flagellar motor. Proc Natl Acad Sci U S A. 1995;92:1970-4 pubmed
    ..This finding suggests that the postulated Mot-protein complex may be in close proximity to FliG at the stator-rotor interface of the flagellar motor. ..
  24. Leake M, Chandler J, Wadhams G, Bai F, Berry R, Armitage J. Stoichiometry and turnover in single, functioning membrane protein complexes. Nature. 2006;443:355-8 pubmed
    ..04 s(-1): the dwell time of a given stator in the motor is only approximately 0.5 min. This is the first direct measurement of the number and rapid turnover of protein subunits within a functioning molecular machine. ..
  25. Sarkar M, Paul K, Blair D. Subunit organization and reversal-associated movements in the flagellar switch of Escherichia coli. J Biol Chem. 2010;285:675-84 pubmed publisher
    ..These results are discussed in the framework of a structurally grounded hypothesis for the switching mechanism. ..
  26. Hauser R, Ceol A, Rajagopala S, Mosca R, Siszler G, Wermke N, et al. A second-generation protein-protein interaction network of Helicobacter pylori. Mol Cell Proteomics. 2014;13:1318-29 pubmed publisher
    ..coli of which one third turned out to be conserved in both species. ..
  27. Brown P, Terrazas M, Paul K, Blair D. Mutational analysis of the flagellar protein FliG: sites of interaction with FliM and implications for organization of the switch complex. J Bacteriol. 2007;189:305-12 pubmed
    ..We propose a model for the organization of FliG and FliM subunits that accounts for the FliG-FliM interactions identified here and for the different copy numbers of FliG and FliM in the flagellum. ..
  28. Yakushi T, Yang J, Fukuoka H, Homma M, Blair D. Roles of charged residues of rotor and stator in flagellar rotation: comparative study using H+-driven and Na+-driven motors in Escherichia coli. J Bacteriol. 2006;188:1466-72 pubmed
    ..coli motor using both rotor and stator components from V. alginolyticus remained sensitive to mutation. Motor function in V. alginolyticus may be enhanced by the proteins MotX and MotY. ..
  29. Scharf B, Fahrner K, Berg H. CheZ has no effect on flagellar motors activated by CheY13DK106YW. J Bacteriol. 1998;180:5123-8 pubmed
    ..Also, CheY** could be cross-linked to FliM, the motor receptor protein, nearly as well as CheY-P. Thus, to CheZ, CheY** looks like CheY, but to FliM, it looks like CheY-P. ..
  30. Toker A, Macnab R. Distinct regions of bacterial flagellar switch protein FliM interact with FliG, FliN and CheY. J Mol Biol. 1997;273:623-34 pubmed
    ..We propose a model in which the N-terminal region of FliM binds to CheY-P, the middle region of FliM binds to FliG, and the C-terminal region binds to FliN. ..
  31. Yuan J, Berg H. Ultrasensitivity of an adaptive bacterial motor. J Mol Biol. 2013;425:1760-4 pubmed publisher
    ..Extreme motor ultrasensitivity broadens our understanding of mechanisms of allostery and serves as an inspiration for future design of synthetic protein switches...
  32. Yamaguchi S, Fujita H, Ishihara A, Aizawa S, Macnab R. Subdivision of flagellar genes of Salmonella typhimurium into regions responsible for assembly, rotation, and switching. J Bacteriol. 1986;166:187-93 pubmed
    Three flagellar genes of Salmonella typhimurium (flaAII.2, flaQ, and flaN) were found to be multifunctional, each being associated with four distinct mutant phenotypes: nonflagellate (Fla-), paralyzed (Mot-), nonchemotactic (Che-) with ..
  33. Sosinsky G, Francis N, DeRosier D, Wall J, Simon M, Hainfeld J. Mass determination and estimation of subunit stoichiometry of the bacterial hook-basal body flagellar complex of Salmonella typhimurium by scanning transmission electron microscopy. Proc Natl Acad Sci U S A. 1992;89:4801-5 pubmed
    ..amp; Aizawa, S.-I. (1990) J. Mol. Biol. 212, 377-387] using quantitative gel electrophoresis. The results of Jones et al., together with ours, account for all proteins in the basal body to within approximately 5% (or 200 kDa). ..
  34. Delalez N, Wadhams G, Rosser G, Xue Q, Brown M, Dobbie I, et al. Signal-dependent turnover of the bacterial flagellar switch protein FliM. Proc Natl Acad Sci U S A. 2010;107:11347-51 pubmed publisher
    ..In many ways the bacterial flagellar motor is as an archetype macromolecular assembly, and our results may have further implications for the functional relevance of protein turnover in other large molecular complexes. ..
  35. Paul K, Gonzalez Bonet G, Bilwes A, Crane B, Blair D. Architecture of the flagellar rotor. EMBO J. 2011;30:2962-71 pubmed publisher
    ..Recently proposed alternative models of rotor assembly, based on a subunit contact observed in crystals, are not supported by experiment. ..
  36. González Pedrajo B, Minamino T, Kihara M, Namba K. Interactions between C ring proteins and export apparatus components: a possible mechanism for facilitating type III protein export. Mol Microbiol. 2006;60:984-98 pubmed
    ..The importance of the C ring as a possible docking site for export substrates, chaperones and FliI through FliH for their efficient delivery to membrane components of the export apparatus is discussed. ..
  37. Kim E, Panushka J, Meyer T, Ide N, Carlisle R, Baker S, et al. Biogenesis of the Flagellar Switch Complex in Escherichia coli: Formation of Sub-Complexes Independently of the Basal-Body MS-Ring. J Mol Biol. 2017;429:2353-2359 pubmed publisher
    ..FliM does not multimerize efficiently by itself but does so in the presence of FliG. Thus, pre-assemblies of the switch-complex proteins can form in the cytosol and might function as intermediates in assembly. ..
  38. Suzuki H, Yonekura K, Namba K. Structure of the rotor of the bacterial flagellar motor revealed by electron cryomicroscopy and single-particle image analysis. J Mol Biol. 2004;337:105-13 pubmed
  39. Tang H, Braun T, Blair D. Motility protein complexes in the bacterial flagellar motor. J Mol Biol. 1996;261:209-21 pubmed
    ..Torque generation in the flagellar motor is thus likely to involve interactions between these two protein complexes. ..
  40. Sourjik V, Berg H. Localization of components of the chemotaxis machinery of Escherichia coli using fluorescent protein fusions. Mol Microbiol. 2000;37:740-51 pubmed
    ..Co-localization with flagellar structures was confirmed by immunofluorescence using an antihook primary antibody. Surprisingly, we did not observe co-localization of CheY with motors, even under conditions in which cells tumbled. ..
  41. Bren A, Eisenbach M. The N terminus of the flagellar switch protein, FliM, is the binding domain for the chemotactic response regulator, CheY. J Mol Biol. 1998;278:507-14 pubmed
    ..These results indicate that the CheY-binding domain of FliM is located at the N terminus, within residues 1 to 16, and suggest that FliM monomers can form a complete site for CheY binding. ..
  42. Zhou J, Sharp L, Tang H, Lloyd S, Billings S, Braun T, et al. Function of protonatable residues in the flagellar motor of Escherichia coli: a critical role for Asp 32 of MotB. J Bacteriol. 1998;180:2729-35 pubmed
    ..We propose that Asp 32 of MotB functions as a proton-binding site in the bacterial flagellar motor and that no other conserved, protonatable residues function in this capacity. ..
  43. Yamaguchi S, Aizawa S, Kihara M, Isomura M, Jones C, Macnab R. Genetic evidence for a switching and energy-transducing complex in the flagellar motor of Salmonella typhimurium. J Bacteriol. 1986;168:1172-9 pubmed
    The flaAII.2, flaQ, and flaN genes of Salmonella typhimurium are important for assembly, rotation, and counterclockwise-clockwise switching of the flagellar motor...
  44. Khan S, Dapice M, Reese T. Effects of mot gene expression on the structure of the flagellar motor. J Mol Biol. 1988;202:575-84 pubmed
    ..The concomitant loss of the rings and motility is consistent with the ring particles having a central role in the flagellar motor. ..
  45. Lowder B, Duyvesteyn M, Blair D. FliG subunit arrangement in the flagellar rotor probed by targeted cross-linking. J Bacteriol. 2005;187:5640-7 pubmed
    ..On the basis of the cross-linking results and the data available from mutational and electron microscopic studies, we propose a model for the organization of FliG subunits in the flagellum. ..
  46. Lee L, Barrett J, Poole R. Genome-wide transcriptional response of chemostat-cultured Escherichia coli to zinc. J Bacteriol. 2005;187:1124-34 pubmed
  47. Lee S, Cho H, Pelton J, Yan D, Henderson R, King D, et al. Crystal structure of an activated response regulator bound to its target. Nat Struct Biol. 2001;8:52-6 pubmed
  48. Kuo S, Koshland D. Sequence of the flaA (cheC) locus of Escherichia coli and discovery of a new gene. J Bacteriol. 1986;166:1007-12 pubmed
    ..The locus was sequenced, and a site of transcriptional initiation was determined. Two reading frames, flaAI and flaAII, span the locus...
  49. Blair D, Berg H. Mutations in the MotA protein of Escherichia coli reveal domains critical for proton conduction. J Mol Biol. 1991;221:1433-42 pubmed
    ..The clustering of the mutations provides independent support for the suggestion that MotA is a transmembrane proton channel and places significant constraints on models for the molecular mechanism of ion conduction. ..
  50. Minamino T, Yamaguchi S, Macnab R. Interaction between FliE and FlgB, a proximal rod component of the flagellar basal body of Salmonella. J Bacteriol. 2000;182:3029-36 pubmed
    ..We suggest that FliE subunits constitute a junction zone between the MS ring and the rod and also that the proximal rod structure consists of FlgB subunits. ..
  51. Garza A, Biran R, Wohlschlegel J, Manson M. Mutations in motB suppressible by changes in stator or rotor components of the bacterial flagellar motor. J Mol Biol. 1996;258:270-85 pubmed
    ..We suggest that most of the suppressors restore motility by introducing compensatory realignments in MotA or FliG. ..
  52. Paul K, Nieto V, Carlquist W, Blair D, Harshey R. The c-di-GMP binding protein YcgR controls flagellar motor direction and speed to affect chemotaxis by a "backstop brake" mechanism. Mol Cell. 2010;38:128-39 pubmed publisher
    ..Inhibition of motility and chemotaxis may represent a strategy to prepare for sedentary existence by disfavoring migration away from a substrate on which a biofilm is to be formed. ..
  53. Chun S, Parkinson J. Bacterial motility: membrane topology of the Escherichia coli MotB protein. Science. 1988;239:276-8 pubmed
    ..Protease treatment of MotB in spheroplasts confirmed this view. The simple transmembrane organization of MotB is difficult to reconcile with a role as a proton conductor. ..