Gene Symbol: flhB
Description: flagellin export apparatus, substrate specificity protein
Alias: ECK1881, JW1869, flaG, yecQ
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Claret L, Calder S, Higgins M, Hughes C. Oligomerization and activation of the FliI ATPase central to bacterial flagellum assembly. Mol Microbiol. 2003;48:1349-55 pubmed
    ..The data reveal central facets of the structure and action of the flagellar assembly ATPase and, by extension, the homologous ATPases of virulence-related type III export systems. ..
  2. Yonekura K, Maki S, Morgan D, DeRosier D, Vonderviszt F, Imada K, et al. The bacterial flagellar cap as the rotary promoter of flagellin self-assembly. Science. 2000;290:2148-52 pubmed
    ..This represents one of the most dynamic movements in protein structures. ..
  3. Thomas J, Stafford G, Hughes C. Docking of cytosolic chaperone-substrate complexes at the membrane ATPase during flagellar type III protein export. Proc Natl Acad Sci U S A. 2004;101:3945-50 pubmed
    ..Membrane localization persisted in fliOPQR, flhB, flhA, fliJ, and fliH null mutants lacking specific flagellar export components but depended on the presence of the ..
  4. Minamino T, Kazetani K, Tahara A, Suzuki H, Furukawa Y, Kihara M, et al. Oligomerization of the bacterial flagellar ATPase FliI is controlled by its extreme N-terminal region. J Mol Biol. 2006;360:510-9 pubmed
  5. Minamino T, Macnab R. Interactions among components of the Salmonella flagellar export apparatus and its substrates. Mol Microbiol. 2000;35:1052-64 pubmed
    ..substrates were strong, whereas those with filament-type substrates were very weak; this may reflect the role of FlhB in substrate specificity switching...
  6. Fraser G, Hirano T, Ferris H, Devgan L, Kihara M, Macnab R. Substrate specificity of type III flagellar protein export in Salmonella is controlled by subdomain interactions in FlhB. Mol Microbiol. 2003;48:1043-57 pubmed
    b>FlhB, an integral membrane protein, gates the type III flagellar export pathway of Salmonella. It permits export of rod/hook-type proteins before hook completion, whereupon it switches specificity to recognize filament-type proteins...
  7. Pallen M, Penn C, Chaudhuri R. Bacterial flagellar diversity in the post-genomic era. Trends Microbiol. 2005;13:143-9 pubmed
    ..Also described is a new family of flagellar proteins, the FlhX proteins, which resemble the cytoplasmic domain of FlhB.
  8. Minamino T, González Pedrajo B, Kihara M, Namba K, Macnab R. The ATPase FliI can interact with the type III flagellar protein export apparatus in the absence of its regulator, FliH. J Bacteriol. 2003;185:3983-8 pubmed
    ..Mutations in the cytoplasmic domains of FlhA and FlhB, which are integral membrane components of the type III flagellar export apparatus, also resulted in substantially ..
  9. Minamino T, Macnab R. Domain structure of Salmonella FlhB, a flagellar export component responsible for substrate specificity switching. J Bacteriol. 2000;182:4906-14 pubmed
    We have investigated the properties of the cytoplasmic domain (FlhB(C)) of the 383-amino-acid Salmonella membrane protein FlhB, a component of the type III flagellar export apparatus...

More Information


  1. Amsler C, Cho M, Matsumura P. Multiple factors underlying the maximum motility of Escherichia coli as cultures enter post-exponential growth. J Bacteriol. 1993;175:6238-44 pubmed
    ..Transcription from the flhB operon and synthesis of flagellin protein similarly peaked in late exponential and early post-exponential phases, ..
  2. Fraser G, González Pedrajo B, Tame J, Macnab R. Interactions of FliJ with the Salmonella type III flagellar export apparatus. J Bacteriol. 2003;185:5546-54 pubmed
    ..We present a model summarizing these multiple interactions. ..
  3. Minamino T, Macnab R. FliH, a soluble component of the type III flagellar export apparatus of Salmonella, forms a complex with FliI and inhibits its ATPase activity. Mol Microbiol. 2000;37:1494-503 pubmed
  4. Kihara M, Minamino T, Yamaguchi S, Macnab R. Intergenic suppression between the flagellar MS ring protein FliF of Salmonella and FlhA, a membrane component of its export apparatus. J Bacteriol. 2001;183:1655-62 pubmed
    ..The data from this study provide genetic support for a model in which at least the FlhA component of the export apparatus physically interacts with the MS ring within which it is housed. ..
  5. Hirano T, Shibata S, Ohnishi K, Tani T, Aizawa S. N-terminal signal region of FliK is dispensable for length control of the flagellar hook. Mol Microbiol. 2005;56:346-60 pubmed
    ..Five genes involved in hook-length regulation are fliK, flhB, fliG, fliM and fliN...
  6. McMurry J, Van Arnam J, Kihara M, Macnab R. Analysis of the cytoplasmic domains of Salmonella FlhA and interactions with components of the flagellar export machinery. J Bacteriol. 2004;186:7586-92 pubmed
    ..proteins are exported via a type III export apparatus which, in part, consists of the membrane proteins FlhA, FlhB, FliO, FliP, FliQ, and FliR and is housed within the membrane-supramembrane ring formed by FliF subunits...
  7. Barker C, Prüss B, Matsumura P. Increased motility of Escherichia coli by insertion sequence element integration into the regulatory region of the flhD operon. J Bacteriol. 2004;186:7529-37 pubmed
    ..7-fold, leading to a 32-fold increase in fliA transcript and a 65-fold increase in flhB::luxCDABE expression from a promoter probe vector...
  8. 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. ..
  9. Moriya N, Minamino T, Hughes K, Macnab R, Namba K. The type III flagellar export specificity switch is dependent on FliK ruler and a molecular clock. J Mol Biol. 2006;359:466-77 pubmed
    Salmonella flagellar hook length is controlled at the level of export substrate specificity of the FlhB component of the type III flagellar export apparatus...
  10. Minamino T, Chu R, Yamaguchi S, Macnab R. Role of FliJ in flagellar protein export in Salmonella. J Bacteriol. 2000;182:4207-15 pubmed
    ..We conclude that FliJ is a general component of the flagellar export apparatus and has a chaperone-like activity for both rod/hook-type and filament-type substrates. ..
  11. Maki S, Vonderviszt F, Furukawa Y, Imada K, Namba K. Plugging interactions of HAP2 pentamer into the distal end of flagellar filament revealed by electron microscopy. J Mol Biol. 1998;277:771-7 pubmed
    ..This also allows us to model the axial domain arrangement of flagellin subunit in the filament. ..
  12. Zarivach R, Deng W, Vuckovic M, Felise H, Nguyen H, Miller S, et al. Structural analysis of the essential self-cleaving type III secretion proteins EscU and SpaS. Nature. 2008;453:124-7 pubmed publisher
    ..related flagellar apparatus, a post-translational cleavage event within the inner membrane proteins EscU/FlhB is required to promote a secretion-competent state...
  13. Zhu K, González Pedrajo B, Macnab R. Interactions among membrane and soluble components of the flagellar export apparatus of Salmonella. Biochemistry. 2002;41:9516-24 pubmed
    ..The components examined were two integral membrane proteins, FlhA and FlhB, and two soluble components, FliH and the ATPase FliI...
  14. Hasegawa K, Yamashita I, Namba K. Quasi- and nonequivalence in the structure of bacterial flagellar filament. Biophys J. 1998;74:569-75 pubmed
  15. Ferris H, Furukawa Y, Minamino T, Kroetz M, Kihara M, Namba K, et al. FlhB regulates ordered export of flagellar components via autocleavage mechanism. J Biol Chem. 2005;280:41236-42 pubmed
    ..One of the export apparatus proteins, FlhB, regulates the substrate specificity of the entire apparatus; i.e...
  16. González Pedrajo B, Fraser G, Minamino T, Macnab R. Molecular dissection of Salmonella FliH, a regulator of the ATPase FliI and the type III flagellar protein export pathway. Mol Microbiol. 2002;45:967-82 pubmed
    ..Based on these data, a model is presented for the domain construction and function of FliH in complex with FliI and FliJ. ..
  17. Maki Yonekura S, Yonekura K, Namba K. Domain movements of HAP2 in the cap-filament complex formation and growth process of the bacterial flagellum. Proc Natl Acad Sci U S A. 2003;100:15528-33 pubmed
  18. Samatey F, Imada K, Nagashima S, Vonderviszt F, Kumasaka T, Yamamoto M, et al. Structure of the bacterial flagellar protofilament and implications for a switch for supercoiling. Nature. 2001;410:331-7 pubmed
    ..By simulated extension of the protofilament model, we have identified possible switch regions responsible for the bi-stable mechanical switch that generates the 0.8 A difference in repeat distance. ..
  19. Kubori T, Sukhan A, Aizawa S, Galan J. Molecular characterization and assembly of the needle complex of the Salmonella typhimurium type III protein secretion system. Proc Natl Acad Sci U S A. 2000;97:10225-30 pubmed
    ..We hypothesize that the needle component may establish the specificity of type III secretion systems in delivering proteins into either plant or animal cells. ..
  20. Kutsukake K, Minamino T, Yokoseki T. Isolation and characterization of FliK-independent flagellation mutants from Salmonella typhimurium. J Bacteriol. 1994;176:7625-9 pubmed
    ..Genetic and sequence analyses of the suppressor mutations revealed that they are located near the 3'-end of the flhB gene, which has been believed to be involved in the early process of the basal body assembly...
  21. McMurry J, Murphy J, González Pedrajo B. The FliN-FliH interaction mediates localization of flagellar export ATPase FliI to the C ring complex. Biochemistry. 2006;45:11790-8 pubmed
    ..A model incorporating the present findings is presented. ..
  22. Minamino T, Ferris H, Moriya N, Kihara M, Namba K. Two parts of the T3S4 domain of the hook-length control protein FliK are essential for the substrate specificity switching of the flagellar type III export apparatus. J Mol Biol. 2006;362:1148-58 pubmed
    ..switch (T3S4) domain of the hook-length control protein FliK, with the integral membrane export apparatus component FlhB. The T3S4 domain of FliK (FliKT3S4) consisting of amino acid residues 265-405 has an unstable and flexible ..
  23. Minamino T, Saijo Hamano Y, Furukawa Y, González Pedrajo B, Macnab R, Namba K. Domain organization and function of Salmonella FliK, a flagellar hook-length control protein. J Mol Biol. 2004;341:491-502 pubmed
    ..apparatus from rod/ hook-type to filament-type by causing a conformational change in the cytoplasmic domain of FlhB (FlhB(C)) upon completion of the hook assembly...
  24. Minamino T, Macnab R. Components of the Salmonella flagellar export apparatus and classification of export substrates. J Bacteriol. 1999;181:1388-94 pubmed
    ..Hook-capping protein (FlgD) and hook protein (FlgE) required FlhA, FlhB, FliH, FliI, FliO, FliP, FliQ, and FliR for their export to the periplasm...
  25. Fan F, Macnab R. Enzymatic characterization of FliI. An ATPase involved in flagellar assembly in Salmonella typhimurium. J Biol Chem. 1996;271:31981-8 pubmed
    ..We propose that FliI has a C-terminal ATPase domain and an N-terminal domain that interacts with other components in the flagellum-specific export apparatus. ..