tonB

Summary

Gene Symbol: tonB
Description: membrane spanning protein in TonB-ExbB-ExbD transport complex
Alias: ECK1246, JW5195, T1rec, exbA
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Gratia J. Studies on defective lysogeny due to chromosomal deletion in Escherichia coli. I. Single lysogens. Biken J. 1966;9:77-87 pubmed
  2. Karlsson M, Hannavy K, Higgins C. A sequence-specific function for the N-terminal signal-like sequence of the TonB protein. Mol Microbiol. 1993;8:379-88 pubmed
    b>TonB is a proline-rich protein which provides a functional link between the inner and outer membranes of Gram-negative bacteria...
  3. Larsen R, Postle K. Conserved residues Ser(16) and His(20) and their relative positioning are essential for TonB activity, cross-linking of TonB with ExbB, and the ability of TonB to respond to proton motive force. J Biol Chem. 2001;276:8111-7 pubmed
    The cytoplasmic membrane protein TonB couples the proton electrochemical potential of the cytoplasmic membrane to transport events at the outer membrane of Gram-negative bacteria...
  4. Clarke T, Tari L, Vogel H. Structural biology of bacterial iron uptake systems. Curr Top Med Chem. 2001;1:7-30 pubmed
    ..evidence also shows that the proteins that provide energy for iron transport at the outer membrane, such as the TonB-ExbB-ExbD system, are structurally very similar across bacterial species...
  5. Khursigara C, De Crescenzo G, Pawelek P, Coulton J. Kinetic analyses reveal multiple steps in forming TonB-FhuA complexes from Escherichia coli. Biochemistry. 2005;44:3441-53 pubmed
    ..The cytoplasmic membrane complex TonB-ExbB-ExbD provides energy for transport via the proton motive force...
  6. Postle K. TonB system, in vivo assays and characterization. Methods Enzymol. 2007;422:245-69 pubmed
    The multiprotein TonB system of Escherichia coli involves proteins in both the cytoplasmic membrane and the outer membrane...
  7. Chang C, Mooser A, Pluckthun A, Wlodawer A. Crystal structure of the dimeric C-terminal domain of TonB reveals a novel fold. J Biol Chem. 2001;276:27535-40 pubmed
    The TonB-dependent complex of Gram-negative bacteria couples the inner membrane proton motive force to the active transport of iron.siderophore and vitamin B(12) across the outer membrane...
  8. Cadieux N, Kadner R. Site-directed disulfide bonding reveals an interaction site between energy-coupling protein TonB and BtuB, the outer membrane cobalamin transporter. Proc Natl Acad Sci U S A. 1999;96:10673-8 pubmed
    ..outer membrane transporter BtuB, the proton motive force, and the trans-periplasmic energy coupling protein TonB. Interaction between TonB and two of the TonB-dependent siderophore transporters has been detected previously by ..
  9. Ködding J, Killig F, Polzer P, Howard S, Diederichs K, Welte W. Crystal structure of a 92-residue C-terminal fragment of TonB from Escherichia coli reveals significant conformational changes compared to structures of smaller TonB fragments. J Biol Chem. 2005;280:3022-8 pubmed
    ..The link between these is TonB, a protein associated with the cytoplasmic membrane, which forms a large periplasmic domain capable of interacting ..

More Information

Publications85

  1. Shultis D, Purdy M, Banchs C, Wiener M. Outer membrane active transport: structure of the BtuB:TonB complex. Science. 2006;312:1396-9 pubmed
    ..electrochemical gradient of protons across the inner membrane, and an inner membrane protein complex (ExbB, ExbD, TonB) that couples the proton-motive force to the outer membrane transporter...
  2. Sean Peacock R, Weljie A, Peter Howard S, Price F, Vogel H. The solution structure of the C-terminal domain of TonB and interaction studies with TonB box peptides. J Mol Biol. 2005;345:1185-97 pubmed
    The TonB protein transduces energy from the proton gradient across the cytoplasmic membrane of Gram-negative bacteria to TonB-dependent outer membrane receptors...
  3. Vakharia Rao H, Kastead K, Savenkova M, Bulathsinghala C, Postle K. Deletion and substitution analysis of the Escherichia coli TonB Q160 region. J Bacteriol. 2007;189:4662-70 pubmed
    ..requires OM transporters and the potential energy of the cytoplasmic membrane (CM) proton gradient and CM proteins TonB, ExbB, and ExbD...
  4. Higgs P, Larsen R, Postle K. Quantification of known components of the Escherichia coli TonB energy transduction system: TonB, ExbB, ExbD and FepA. Mol Microbiol. 2002;44:271-81 pubmed
    The TonB-dependent energy transduction system couples cytoplasmic membrane proton motive force to active transport of iron-siderophore complexes across the outer membrane in Gram-negative bacteria...
  5. Garcia Herrero A, Peacock R, Howard S, Vogel H. The solution structure of the periplasmic domain of the TonB system ExbD protein reveals an unexpected structural homology with siderophore-binding proteins. Mol Microbiol. 2007;66:872-89 pubmed
    ..of iron complexes through outer membrane transporters from Gram-negative bacteria is highly dependent on the TonB system...
  6. Carter D, Gagnon J, Damlaj M, Mandava S, Makowski L, Rodi D, et al. Phage display reveals multiple contact sites between FhuA, an outer membrane receptor of Escherichia coli, and TonB. J Mol Biol. 2006;357:236-51 pubmed
    ..b>TonB-ExbB-ExbD transduces energy from the cytoplasmic membrane to the OM by contacts between TonB and OM receptors that ..
  7. Ghosh J, Postle K. Evidence for dynamic clustering of carboxy-terminal aromatic amino acids in TonB-dependent energy transduction. Mol Microbiol. 2004;51:203-13 pubmed
    Escherichia coli uses the proton motive force of the cytoplasmic membrane and TonB protein to energize the active transport of iron-siderophores and vitamin B12 across the outer membrane...
  8. Chu B, Peacock R, Vogel H. Bioinformatic analysis of the TonB protein family. Biometals. 2007;20:467-83 pubmed
    b>TonB is a protein prevalent in a large number of Gram-negative bacteria that is believed to be responsible for the energy transduction component in the import of ferric iron complexes and vitamin B(12) across the outer membrane...
  9. Larsen R, Deckert G, Kastead K, Devanathan S, Keller K, Postle K. His(20) provides the sole functionally significant side chain in the essential TonB transmembrane domain. J Bacteriol. 2007;189:2825-33 pubmed
    The cytoplasmic membrane protein TonB couples the protonmotive force of the cytoplasmic membrane to active transport across the outer membrane of Escherichia coli...
  10. Letain T, Postle K. TonB protein appears to transduce energy by shuttling between the cytoplasmic membrane and the outer membrane in Escherichia coli. Mol Microbiol. 1997;24:271-83 pubmed
    ..b>TonB protein is required in this process to transduce cytoplasmic membrane energy to the outer membrane...
  11. Devanathan S, Postle K. Studies on colicin B translocation: FepA is gated by TonB. Mol Microbiol. 2007;65:441-53 pubmed
    Colicin B is a 55 kDa dumbbell-shaped protein toxin that uses the TonB system (outer membrane transporter, FepA, and three cytoplasmic membrane proteins TonB/ExbB/ExbD) to enter and kill Escherichia coli...
  12. Fischer E, Gunter K, Braun V. Involvement of ExbB and TonB in transport across the outer membrane of Escherichia coli: phenotypic complementation of exb mutants by overexpressed tonB and physical stabilization of TonB by ExbB. J Bacteriol. 1989;171:5127-34 pubmed
    The exb locus in Escherichia coli consists of two genes, termed exbB and exbD. Exb functions are related to TonB function in that most TonB-dependent processes are enhanced by Exb...
  13. Larsen R, Thomas M, Postle K. Protonmotive force, ExbB and ligand-bound FepA drive conformational changes in TonB. Mol Microbiol. 1999;31:1809-24 pubmed
    b>TonB couples the cytoplasmic membrane protonmotive force (pmf) to active transport across the outer membrane, potentially through a series of conformational changes...
  14. Sauter A, Howard S, Braun V. In vivo evidence for TonB dimerization. J Bacteriol. 2003;185:5747-54 pubmed
    b>TonB, in complex with ExbB and ExbD, is required for the energy-dependent transport of ferric siderophores across the outer membrane of Escherichia coli, the killing of cells by group B colicins, and infection by phages T1 and phi80...
  15. Braun V. Iron uptake by Escherichia coli. Front Biosci. 2003;8:s1409-21 pubmed
    ..is provided by the proton motive force of the cytoplasmic membrane and transmitted to the outer membrane via the TonB-ExbB-ExbD proteins...
  16. Ghosh J, Postle K. Disulphide trapping of an in vivo energy-dependent conformation of Escherichia coli TonB protein. Mol Microbiol. 2005;55:276-88 pubmed
    In Escherichia coli, the TonB system transduces the protonmotive force (pmf) of the cytoplasmic membrane to support a variety of transport events across the outer membrane...
  17. Pawelek P, Croteau N, Ng Thow Hing C, Khursigara C, Moiseeva N, Allaire M, et al. Structure of TonB in complex with FhuA, E. coli outer membrane receptor. Science. 2006;312:1399-402 pubmed
    The cytoplasmic membrane protein TonB spans the periplasm of the Gram-negative bacterial cell envelope, contacts cognate outer membrane receptors, and facilitates siderophore transport...
  18. Kadner R, Heller K. Mutual inhibition of cobalamin and siderophore uptake systems suggests their competition for TonB function. J Bacteriol. 1995;177:4829-35 pubmed
    ..The first step is mediated by substrate-specific outer membrane transport proteins and the energy-coupling TonB protein complex, and the second step uses separate periplasmic permeases for transport across the cytoplasmic ..
  19. Ollis A, Manning M, Held K, Postle K. Cytoplasmic membrane protonmotive force energizes periplasmic interactions between ExbD and TonB. Mol Microbiol. 2009;73:466-81 pubmed publisher
    The TonB system of Escherichia coli (TonB/ExbB/ExbD) transduces the protonmotive force (pmf) of the cytoplasmic membrane to drive active transport by high-affinity outer membrane transporters...
  20. Braun V. Energy-coupled transport and signal transduction through the gram-negative outer membrane via TonB-ExbB-ExbD-dependent receptor proteins. FEMS Microbiol Rev. 1995;16:295-307 pubmed
    ..Energy flows from the cytoplasmic into the outer membrane via a complex consisting of the TonB, ExbB and ExbD proteins which are anchored in the cytoplasmic membrane...
  21. Kohanski M, Dwyer D, Hayete B, Lawrence C, Collins J. A common mechanism of cellular death induced by bactericidal antibiotics. Cell. 2007;130:797-810 pubmed
    ..g., reca. ..
  22. Young G, Postle K. Repression of tonB transcription during anaerobic growth requires Fur binding at the promoter and a second factor binding upstream. Mol Microbiol. 1994;11:943-54 pubmed
    ..In Gram-negative bacteria a central target for regulation is the TonB protein, an energy transducer that couples the cytoplasmic membrane proton motive force to active transport of (..
  23. Agemizu Y, Uematsu N, Yamamoto K. DNA sequence analysis of spontaneous tonB deletion mutations in a polA1 strain of Escherichia coli K12. Biochem Biophys Res Commun. 1999;261:584-9 pubmed
    By DNA sequence analysis, we have determined a spectrum of 61 spontaneous mutations occurring in the endogenous tonB gene in the polA1 strain of Escherichia coli. The overall mutation frequency was approximately 2...
  24. Postle K, Larsen R. TonB-dependent energy transduction between outer and cytoplasmic membranes. Biometals. 2007;20:453-65 pubmed
    The TonB system of Escherichia coli (and most other Gram-negative bacteria) is distinguished by its importance to iron acquisition, its contribution to bacterial pathogenesis, and a unique and mysterious mechanism of action...
  25. Ollis A, Postle K. The same periplasmic ExbD residues mediate in vivo interactions between ExbD homodimers and ExbD-TonB heterodimers. J Bacteriol. 2011;193:6852-63 pubmed publisher
    The TonB system couples cytoplasmic membrane proton motive force to TonB-gated outer membrane transporters for active transport of nutrients into the periplasm...
  26. Postle K, Reznikoff W. Identification of the Escherichia coli tonB gene product in minicells containing tonB hybrid plasmids. J Mol Biol. 1979;131:619-36 pubmed
  27. Mora L, Klepsch M, Buckingham R, Heurgué Hamard V, Kervestin S, de Zamaroczy M. Dual roles of the central domain of colicin D tRNase in TonB-mediated import and in immunity. J Biol Chem. 2008;283:4993-5003 pubmed
    Colicin D import into Escherichia coli requires an interaction via its TonB box with the energy transducer TonB. Colicin D cytotoxicity is inhibited by specific tonB mutations, but it is restored by suppressor mutations in the TonB box...
  28. Langenscheid J, Killmann H, Braun V. A FhuA mutant of Escherichia coli is infected by phage T1-independent of TonB. FEMS Microbiol Lett. 2004;234:133-7 pubmed
    Infection of Escherichia coli K-12 by phages T1 and phi 80 requires the FhuA outer membrane protein and the TonB protein. Mutations in the N-terminal globular domain close to the predicted channel in the beta-barrel of FhuA were created...
  29. Lill Y, Jordan L, Smallwood C, Newton S, Lill M, Klebba P, et al. Confined Mobility of TonB and FepA in Escherichia coli Membranes. PLoS ONE. 2016;11:e0160862 pubmed publisher
    ..many cases, involves transit of the nutrient through a class of beta-barrel proteins in the outer membrane known as TonB-dependent transporters (TBDTs) and requires interaction with the inner membrane protein TonB...
  30. Germon P, Ray M, Vianney A, Lazzaroni J. Energy-dependent conformational change in the TolA protein of Escherichia coli involves its N-terminal domain, TolQ, and TolR. J Bacteriol. 2001;183:4110-4 pubmed
    ..They share homology with the ExbB, ExbD, and TonB proteins, respectively...
  31. Wright G. On the road to bacterial cell death. Cell. 2007;130:781-3 pubmed
    ..In this issue, Kohanski et al. (2007) provide evidence that the production of reactive oxygen species is a shared mechanism of cell death initiated by bactericidal antibiotics. ..
  32. Traub I, Gaisser S, Braun V. Activity domains of the TonB protein. Mol Microbiol. 1993;8:409-23 pubmed
    ..bacteria contain an energy-coupled transport system through the outer membrane which consists of the proteins TonB, ExbB, ExbD anchored in the cytoplasmic membrane and receptors in the outer membrane...
  33. Gresock M, Kastead K, Postle K. From Homodimer to Heterodimer and Back: Elucidating the TonB Energy Transduction Cycle. J Bacteriol. 2015;197:3433-45 pubmed publisher
    The TonB system actively transports large, scarce, and important nutrients through outer membrane (OM) transporters of Gram-negative bacteria using the proton gradient of the cytoplasmic membrane (CM)...
  34. Ogierman M, Braun V. Interactions between the outer membrane ferric citrate transporter FecA and TonB: studies of the FecA TonB box. J Bacteriol. 2003;185:1870-85 pubmed
    ..The energy is transduced to FecA by the inner membrane complex, TonB, ExbB, and ExbD...
  35. Frost G, Rosenberg H. Relationship between the tonB locus and iron transport in Escherichia coli. J Bacteriol. 1975;124:704-12 pubmed
    ..arcB-) of Escherichia coli, unable to synthesize the iron transport compound enterochelin, was transduced to tonB-, it became resistant to phage phi80 and simultaneously lost the growth response to enterochelin and the ability to ..
  36. Higgs P, Myers P, Postle K. Interactions in the TonB-dependent energy transduction complex: ExbB and ExbD form homomultimers. J Bacteriol. 1998;180:6031-8 pubmed
    The cytoplasmic membrane proteins ExbB and ExbD support TonB-dependent active transport of iron siderophores and vitamin B12 across the essentially unenergized outer membrane of Escherichia coli...
  37. Higgs P, Letain T, Merriam K, Burke N, Park H, Kang C, et al. TonB interacts with nonreceptor proteins in the outer membrane of Escherichia coli. J Bacteriol. 2002;184:1640-8 pubmed
    The Escherichia coli TonB protein serves to couple the cytoplasmic membrane proton motive force to active transport of iron-siderophore complexes and vitamin B(12) across the outer membrane...
  38. James K, Hancock M, Moreau V, Molina F, Coulton J. TonB induces conformational changes in surface-exposed loops of FhuA, outer membrane receptor of Escherichia coli. Protein Sci. 2008;17:1679-88 pubmed publisher
    ..Cytoplasmic membrane-anchored TonB transduces energy to FhuA to facilitate siderophore transport...
  39. Khursigara C, De Crescenzo G, Pawelek P, Coulton J. Enhanced binding of TonB to a ligand-loaded outer membrane receptor: role of the oligomeric state of TonB in formation of a functional FhuA.TonB complex. J Biol Chem. 2004;279:7405-12 pubmed
    ..Energy for transport is provided by the cytoplasmic membrane complex TonB.ExbB.ExbD, which uses the proton motive force of the cytoplasmic membrane to transduce energy to the outer membrane...
  40. Pramanik A, Hauf W, Hoffmann J, Cernescu M, Brutschy B, Braun V. Oligomeric structure of ExbB and ExbB-ExbD isolated from Escherichia coli as revealed by LILBID mass spectrometry. Biochemistry. 2011;50:8950-6 pubmed publisher
    ..from the proton-motive force of the cytoplasmic membrane, which is coupled to the outer membrane via the ExbB-ExbD-TonB protein complex...
  41. Peacock R, Andrushchenko V, Demcoe A, Gehmlich M, Lu L, Herrero A, et al. Characterization of TonB interactions with the FepA cork domain and FecA N-terminal signaling domain. Biometals. 2006;19:127-42 pubmed
    The mechanism of TonB dependent siderophore uptake through outer membrane transporters in Gram-negative bacteria is poorly understood...
  42. Postle K, Good R. A bidirectional rho-independent transcription terminator between the E. coli tonB gene and an opposing gene. Cell. 1985;41:577-85 pubmed
    We identified an Escherichia coli gene, designated P14, that is adjacent to and in the opposite orientation to the tonB gene...
  43. Uematsu N, Matsuoka C, Agemizu Y, Nagoshi E, Yamamoto K. Asymmetric crossing over in the spontaneous formation of large deletions in the tonB-trp region of the Escherichia coli K-12 chromosome. Mol Gen Genet. 1999;261:523-9 pubmed
    The chromosomal tonB gene of Escherichia coli was used as a target for the detection of spontaneous deletion mutations...
  44. Carter D, Miousse I, Gagnon J, Martinez E, Clements A, Lee J, et al. Interactions between TonB from Escherichia coli and the periplasmic protein FhuD. J Biol Chem. 2006;281:35413-24 pubmed
    For uptake of ferrichrome into bacterial cells, FhuA, a TonB-dependent outer membrane receptor of Escherichia coli, is required...
  45. Karlsson M, Hannavy K, Higgins C. ExbB acts as a chaperone-like protein to stabilize TonB in the cytoplasm. Mol Microbiol. 1993;8:389-96 pubmed
    The TonB protein is required to transduce energy from the cytoplasmic membrane to outer membrane transport proteins of Gram-negative bacteria...
  46. Freed D, Lukasik S, Sikora A, Mokdad A, Cafiso D. Monomeric TonB and the Ton box are required for the formation of a high-affinity transporter-TonB complex. Biochemistry. 2013;52:2638-48 pubmed publisher
    ..Gram-negative bacteria involves the coupling of an outer membrane transport protein to the transperiplasmic protein TonB. In this study, a soluble construct of Escherichia coli TonB (residues 33-239) was used to determine the affinity ..
  47. Rowbury R, Hussain N. Exposure of Escherichia coli to acid habituation conditions sensitizes it to alkaline stress. Lett Appl Microbiol. 1996;22:57-61 pubmed
    ..5 plus DNA gyrase inhibitors and was markedly reduced by himA, himD, hns, ompC and nhaA lesions. A tonB deletion mutant showed alkali sensitivity at pHo 7.0...
  48. Killmann H, Herrmann C, Torun A, Jung G, Braun V. TonB of Escherichia coli activates FhuA through interaction with the beta-barrel. Microbiology. 2002;148:3497-509 pubmed
    ..functions except infection by phage T5, and is thought to be mediated to the outer-membrane receptor FhuA by the TonB protein. The crystal structure of FhuA consists of a beta-barrel that is closed by a globular domain...
  49. Braun V, Gunter K, Hantke K. Transport of iron across the outer membrane. Biol Met. 1991;4:14-22 pubmed
    The TonB protein is involved in energ-coupled receptor-dependent transport processes across the outer membrane. The TonB protein is anchored in the cytoplasmic membrane but exposed to the periplasmic space...
  50. Larsen R, Letain T, Postle K. In vivo evidence of TonB shuttling between the cytoplasmic and outer membrane in Escherichia coli. Mol Microbiol. 2003;49:211-8 pubmed
    ..The transduction of energy is mediated by TonB protein...
  51. Cadieux N, Bradbeer C, Reeger Schneider E, Koster W, Mohanty A, Wiener M, et al. Identification of the periplasmic cobalamin-binding protein BtuF of Escherichia coli. J Bacteriol. 2002;184:706-17 pubmed
    ..Transport of CN-Cbl across the outer membrane and its accumulation in the periplasm is mediated by the TonB-dependent transporter BtuB...
  52. Postle K. TonB protein and energy transduction between membranes. J Bioenerg Biomembr. 1993;25:591-601 pubmed
    b>TonB protein couples cytoplasmic membrane electrochemical potential to active transport of iron-siderophore complexes and vitamin B12 through high-affinity outer membrane receptors of Gram-negative bacteria...
  53. Braun V, Braun M. Active transport of iron and siderophore antibiotics. Curr Opin Microbiol. 2002;5:194-201 pubmed
    ..complexes and in response to energy transfer from the cytoplasmic membrane into the outer membrane via the TonB-ExbB-ExbD protein complex...
  54. Guarente L, Mitchell D, Beckwith J. Transcription termination at the end of the tryptophan operon of Escherichia coli. J Mol Biol. 1977;112:423-36 pubmed
  55. Gumbart J, Wiener M, Tajkhorshid E. Mechanics of force propagation in TonB-dependent outer membrane transport. Biophys J. 2007;93:496-504 pubmed
    ..Here, we examine the interaction of TonB, an inner membrane protein, with an outer membrane transporter based upon a recent crystal structure of a TonB-..
  56. Shultis D, Purdy M, Banchs C, Wiener M. Crystallization and preliminary X-ray crystallographic analysis of the Escherichia coli outer membrane cobalamin transporter BtuB in complex with the carboxy-terminal domain of TonB. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006;62:638-41 pubmed
    ..membrane active-transport proteins that utilize the proton-motive force of the inner membrane via coupling to the TonB protein...
  57. Braun V, Frenz J, Hantke K, Schaller K. Penetration of colicin M into cells of Escherichia coli. J Bacteriol. 1980;142:162-8 pubmed
    ..Insensitive tonA and tonB mutants became sensitive to colicin M upon treatment by osmotic shock, whereas the tolM mutants remained ..
  58. Kadner R. Vitamin B12 transport in Escherichia coli: energy coupling between membranes. Mol Microbiol. 1990;4:2027-33 pubmed
    ..outer-membrane proteins carry out the energy-dependent transport across the outer membrane, in conjunction with the TonB coupling protein...
  59. Bassford P, Bradbeer C, Kadner R, Schnaitman C. Transport of vitamin B12 in tonB mutants of Escherichia coli. J Bacteriol. 1976;128:242-7 pubmed
    It is known that the tonB mutation in Escherichia coli is responsible for a defect in the transport of iron chelates. These are transported by systems that involve outer membrane components...
  60. Howard S, Herrmann C, Stratilo C, Braun V. In vivo synthesis of the periplasmic domain of TonB inhibits transport through the FecA and FhuA iron siderophore transporters of Escherichia coli. J Bacteriol. 2001;183:5885-95 pubmed
    ..motive force is postulated to be transduced to the transport proteins by a protein complex that consists of the TonB, ExbB, and ExbD proteins...
  61. Koedding J, Howard P, Kaufmann L, Polzer P, Lustig A, Welte W. Dimerization of TonB is not essential for its binding to the outer membrane siderophore receptor FhuA of Escherichia coli. J Biol Chem. 2004;279:9978-86 pubmed
    ..is provided by the proton motive force of the cytoplasmic membrane and is transmitted to FhuA by the protein TonB. Although the structure of full-length TonB is not known, the structure of the last 77 residues of a fragment ..
  62. Nagata Y, Kawata M, Komura J, Ono T, Yamamoto K. X-ray-induced mutations in Escherichia coli K-12 strains with altered DNA polymerase I activities. Mutat Res. 2003;528:93-103 pubmed
    Spectra of ionizing radiation mutagenesis were determined by sequencing X-ray-induced endogenous tonB gene mutations in Escherichia coli polA strains...
  63. Braun V, Gaisser S, Herrmann C, Kampfenkel K, Killmann H, Traub I. Energy-coupled transport across the outer membrane of Escherichia coli: ExbB binds ExbD and TonB in vitro, and leucine 132 in the periplasmic region and aspartate 25 in the transmembrane region are important for ExbD activity. J Bacteriol. 1996;178:2836-45 pubmed
    ..membrane is transferred to the outer membrane with the aid of the Ton system, consisting of the proteins TonB, ExbB, and ExbD. In this paper we describe two point mutations which inactivate ExbD...
  64. Kaserer W, Jiang X, Xiao Q, Scott D, Bauler M, Copeland D, et al. Insight from TonB hybrid proteins into the mechanism of iron transport through the outer membrane. J Bacteriol. 2008;190:4001-16 pubmed publisher
    We created hybrid proteins to study the functions of TonB. We first fused the portion of Escherichia coli tonB that encodes the C-terminal 69 amino acids (amino acids 170 to 239) of TonB downstream from E. coli malE (MalE-TonB69C)...
  65. Postle K, Skare J. Escherichia coli TonB protein is exported from the cytoplasm without proteolytic cleavage of its amino terminus. J Biol Chem. 1988;263:11000-7 pubmed
    The requirement for TonB protein in a variety of membrane-related processes suggests that TonB is an envelope protein. Consistent with this suggestion, the deduced TonB amino acid sequence (Postle, K., and Good, R. F., (1983) Proc. Natl...
  66. Dorman C, Barr G, Ni Bhriain N, Higgins C. DNA supercoiling and the anaerobic and growth phase regulation of tonB gene expression. J Bacteriol. 1988;170:2816-26 pubmed
    ..Negative supercoiling of DNA in vivo is increased by anaerobic growth and is also influenced by growth phase. The tonB promoter of Escherichia coli and Salmonella typhimurium was found to be highly sensitive to changes in DNA ..
  67. Mashimo K, Nagata Y, Kawata M, Iwasaki H, Yamamoto K. Role of the RuvAB protein in avoiding spontaneous formation of deletion mutations in the Escherichia coli K-12 endogenous tonB gene. Biochem Biophys Res Commun. 2004;323:197-203 pubmed
    The endogenous tonB gene of Escherichia coli was used as a target for spontaneous deletion mutations which were isolated from ruvAB-, recG-, and ruvC- cells...
  68. Traub I, Braun V. Energy-coupled colicin transport through the outer membrane of Escherichia coli K-12: mutated TonB proteins alter receptor activities and colicin uptake. FEMS Microbiol Lett. 1994;119:65-70 pubmed
    The current model of TonB-dependent colicin transport through the outer membrane of Escherichia coli proposes initial binding to receptor proteins, vectorial release from the receptors and uptake into the periplasm from where the colicins,..
  69. Schöffler H, Braun V. Transport across the outer membrane of Escherichia coli K12 via the FhuA receptor is regulated by the TonB protein of the cytoplasmic membrane. Mol Gen Genet. 1989;217:378-83 pubmed
    Point mutations in the "TonB box" of fhuA were suppressed by point mutations in the tonB gene, suggesting both a functional and physical interaction between the FhuA receptor protein in the outer membrane and the TonB protein in ..
  70. Gottesman S, Beckwith J. Directed transposition of the arabinose operon: a technique for the isolation of specialized transducing bacteriophages for any Escherichia coli gene. J Mol Biol. 1969;44:117-27 pubmed
  71. Lloubes R, Cascales E, Walburger A, Bouveret E, Lazdunski C, Bernadac A, et al. The Tol-Pal proteins of the Escherichia coli cell envelope: an energized system required for outer membrane integrity?. Res Microbiol. 2001;152:523-9 pubmed
    ..However, outer membrane proteins together with the Tol-Pal and TonB systems have been exploited for the entry of macromolecules such as bacteriocins and phage DNA through the ..
  72. Postle K, Kastead K, Gresock M, Ghosh J, Swayne C. The TonB dimeric crystal structures do not exist in vivo. MBio. 2010;1: pubmed publisher
    The TonB system energizes transport of nutrients across the outer membrane of Escherichia coli using cytoplasmic membrane proton motive force (PMF) for energy...
  73. Ollis A, Kumar A, Postle K. The ExbD periplasmic domain contains distinct functional regions for two stages in TonB energization. J Bacteriol. 2012;194:3069-77 pubmed publisher
    The TonB system of gram-negative bacteria energizes the active transport of diverse nutrients through high-affinity TonB-gated outer membrane transporters using energy derived from the cytoplasmic membrane proton motive force...
  74. Cadieux N, Phan P, Cafiso D, Kadner R. Differential substrate-induced signaling through the TonB-dependent transporter BtuB. Proc Natl Acad Sci U S A. 2003;100:10688-93 pubmed
    The BtuB transporter mediates high-affinity binding and TonB-dependent active transport of vitamin B12 [cyanocobalamin (CNCbl)] across the outer membrane of Escherichia coli...
  75. Killmann H, Braun M, Herrmann C, Braun V. FhuA barrel-cork hybrids are active transporters and receptors. J Bacteriol. 2001;183:3476-87 pubmed
    ..It has been assumed that the proton motive force of the cytoplasmic membrane through the interaction of the TonB protein with the TonB box of the cork opens the FhuA channel...
  76. Braun V, Herrmann C. Evolutionary relationship of uptake systems for biopolymers in Escherichia coli: cross-complementation between the TonB-ExbB-ExbD and the TolA-TolQ-TolR proteins. Mol Microbiol. 1993;8:261-8 pubmed
    ..Group B colicins, ferric siderophores and vitamin B12 are taken up via the TonB-ExbB-ExbD, group A colicins via the TolA-TolQ-TolR system...