Gene Symbol: fliN
Description: flagellar motor switching and energizing component
Alias: ECK1944, JW1930, motD
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. 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). ..
  2. 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
    ..Our results suggest that within the corresponding gene products there are specialized subregions for flagellar structure, motor rotation, and control of the sense of rotation. ..
  3. 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. ..
  4. 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. ..
  5. 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
    ..In Escherichia coli and Salmonella, the switch complex contains the proteins FliG, FliM, and FliN and corresponds structurally with the C-ring in the flagellar basal body...
  6. 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. ..
  7. 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. ..
  8. 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. ..
  9. 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 flagellar switch proteins of Salmonella, FliG, FliM and FliN, participate in the switching of motor rotation, torque generation and flagellar assembly/export. FliN has been implicated in the flagellar export process...

More Information


  1. 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
    Five proteins (MotA, MotB, FliG, FliM, and FliN) have been implicated in energizing flagellar rotation in Escherichia coli and Salmonella typhimurium...
  2. Hashimoto M, Mashimo T, Hirano T, Yamaguchi S, Aizawa S. Functional roles of the hook in a rotating tethered cell. J Mol Biol. 2008;375:367-75 pubmed
    ..To analyze the detailed manner of rotation, we have constructed and expressed yellow fluorescent protein (YFP)-FliN fusion protein in a fliN deletion mutant, resulting in the recovery of motility of the Fla(-) mutant cells...
  3. 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. ..
  4. 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
    ..This switch complex is probably mounted to the base of the flagellar basal body and, via binding of the CheY and CheZ proteins, receives sensory information and uses it to control flagellar operation. ..
  5. 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
    The FliG, FliM, and FliN proteins of the bacterial flagellar motor are believed to interact with one another to form the switch complex, which in turn is thought to interact with one of the chemotaxis proteins, CheY...
  6. 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
    ..FliG is a soluble protein located on the cytoplasmic face of the rotor. Two other proteins, FliM and FliN, are known to bind to FliG and have also been suggested to be involved to some extent in torque generation...
  7. 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
    Five proteins (MotA, MotB, FliG, FliM and FliN) may be involved in energizing flagellar rotation in Escherichia coli...
  8. Tang H, Braun T, Blair D. Motility protein complexes in the bacterial flagellar motor. J Mol Biol. 1996;261:209-21 pubmed
    ..These are MotA, MotB, FliG, FliM and FliN. In this study, we have probed binding interactions among these proteins, by using protein fusions to glutathione S-..
  9. 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. ..
  10. 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
  11. 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. ..
  12. Branch R, Sayegh M, Shen C, Nathan V, Berg H. Adaptive remodelling by FliN in the bacterial rotary motor. J Mol Biol. 2014;426:3314-3324 pubmed publisher
    ..It is difficult to reconcile this FliM remodelling with the observation that partner FliN subunits are relatively static fixtures in the motor...
  13. 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. ..
  14. 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. ..
  15. 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. ..
  16. 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. ..
  17. 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. ..
  18. 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
    ..and clockwise rotation are controlled by a "switch complex" composed of three proteins (FliG, FliM, and FliN) and located at the base of the flagellar motor. The mechanism of function of the switch is unknown...
  19. 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
  20. 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. ..
  21. 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. ..
  22. 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. ..
  23. 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
    ..that drives the flagellar filament of Escherichia coli contains three "switch" proteins (FliG, FliM, and FliN) that together determine the direction of rotation...
  24. 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
    ..To address this question, we purified the intact switch complex (constituting the switch proteins FliG, FliM, and FliN and the scaffolding protein FliF) in quantities sufficient for biochemical work and used it to investigate whether ..
  25. 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
    FliG, FliM, and FliN, key proteins for torque generation, are located in two rings. The first protein is in the M ring and the last two are in the C ring...
  26. 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. ..
  27. 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. ..
  28. 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. ..
  29. Minamino T, Yoshimura S, Morimoto Y, Gonz lez Pedrajo B, Kami ike N, Namba K. Roles of the extreme N-terminal region of FliH for efficient localization of the FliH-FliI complex to the bacterial flagellar type III export apparatus. Mol Microbiol. 2009;74:1471-83 pubmed publisher
    ..The FliH-FliI complex also binds to the C ring of the basal body through a FliH-FliN interaction for efficient export. However, it remains unclear how these reactions proceed within the cell...
  30. 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
    ..glycines, and to the spa24 gene of the Shigella flexneri. The latter two genes encode proteins that appear to be involved in protein translocation, suggesting that the FliP protein may have a similar function...
  31. 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
  32. 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...
  33. 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
    ..Three motor proteins, FliG, FliM, and FliN, have been implicated in this process...
  34. 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. ..
  35. Brown P, Mathews M, Joss L, Hill C, Blair D. Crystal structure of the flagellar rotor protein FliN from Thermotoga maritima. J Bacteriol. 2005;187:2890-902 pubmed publisher
    b>FliN is a component of the bacterial flagellum that is present at levels of more than 100 copies and forms the bulk of the C ring, a drum-shaped structure at the inner end of the basal body...
  36. 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. ..
  37. Paul K, Blair D. Organization of FliN subunits in the flagellar motor of Escherichia coli. J Bacteriol. 2006;188:2502-11 pubmed
    b>FliN is a major constituent of the C ring in the flagellar basal body of many bacteria...
  38. 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
    ..The MotD (now called FliN) protein, a flagellar switch protein, was determined to have an apparent molecular weight of 16,000, and the FlaAI (..
  39. 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. ..
  40. 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. ..
  41. 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