Gene Symbol: tar
Description: methyl-accepting chemotaxis protein II
Alias: ECK1887, JW1875, cheM
Species: Escherichia coli str. K-12 substr. MG1655
Products:     tar

Top Publications

  1. Yang Y, Inouye M. Intermolecular complementation between two defective mutant signal-transducing receptors of Escherichia coli. Proc Natl Acad Sci U S A. 1991;88:11057-61 pubmed
    Taz1 is a hybrid signal-transducing membrane receptor between Tar, an aspartate chemoreceptor, and EnvZ, an osmosensor of Escherichia coli that is able to induce ompC expression by phosphorylating OmpR (a transcriptional activator) in ..
  2. Tatsuno I, Lee L, Kawagishi I, Homma M, Imae Y. Transmembrane signalling by the chimeric chemosensory receptors of Escherichia coli Tsr and Tar with heterologous membrane-spanning regions. Mol Microbiol. 1994;14:755-62 pubmed
    The serine and aspartate chemosensory receptors (Tsr and Tar) of Escherichia coli have two membrane-spanning regions TM1 and TM2...
  3. Draheim R, Bormans A, Lai R, Manson M. Tryptophan residues flanking the second transmembrane helix (TM2) set the signaling state of the Tar chemoreceptor. Biochemistry. 2005;44:1268-77 pubmed
    ..In the high-abundance receptors Tar and Tsr, TM2 is flanked by tryptophan residues, which should localize preferentially to the interfacial zone ..
  4. Shih Y, Kawagishi I, Rothfield L. The MreB and Min cytoskeletal-like systems play independent roles in prokaryotic polar differentiation. Mol Microbiol. 2005;58:917-28 pubmed
    ..targeting of other polar constituents, such as the Shigella virulence factor IcsA and the aspartate chemoreceptor Tar, in a process that is independent of the Min system...
  5. Shrout A, Montefusco D, Weis R. Template-directed assembly of receptor signaling complexes. Biochemistry. 2003;42:13379-85 pubmed
    ..self-assembled clusters of a receptor fragment (CF) derived from the cytoplasmic domain of the aspartate receptor, Tar. Histidine-tagged Tar CF was assembled on the surface of sonicated unilamellar vesicles via a lipid containing the ..
  6. Shiomi D, Yoshimoto M, Homma M, Kawagishi I. Helical distribution of the bacterial chemoreceptor via colocalization with the Sec protein translocation machinery. Mol Microbiol. 2006;60:894-906 pubmed
    ..Here we examined whether the aspartate chemoreceptor (Tar) is inserted directly into the polar membrane by using its fusion to green fluorescent protein (GFP)...
  7. 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. ..
  8. Schulmeister S, Ruttorf M, Thiem S, Kentner D, Lebiedz D, Sourjik V. Protein exchange dynamics at chemoreceptor clusters in Escherichia coli. Proc Natl Acad Sci U S A. 2008;105:6403-8 pubmed publisher
    ..Our results indicate that the rates of protein turnover at the cluster have evolved to ensure optimal performance of the chemotaxis pathway. ..
  9. Lai R, Manson J, Bormans A, Draheim R, Nguyen N, Manson M. Cooperative signaling among bacterial chemoreceptors. Biochemistry. 2005;44:14298-307 pubmed
    ..The ability of homogeneous populations of the serine receptor Tsr and the aspartate receptor Tar to stimulate CheA was directly proportional to the ratio of the receptor to total protein in cell membranes up to a ..

More Information


  1. Derr P, Boder E, Goulian M. Changing the specificity of a bacterial chemoreceptor. J Mol Biol. 2006;355:923-32 pubmed
    ..We have applied this method to select for variants of the Escherichia coli aspartate receptor, Tar, that have a new or improved response to different amino acids...
  2. Draheim R, Bormans A, Lai R, Manson M. Tuning a bacterial chemoreceptor with protein-membrane interactions. Biochemistry. 2006;45:14655-64 pubmed
    ..near the cytoplasmic end of TM2, helps maintain the normal baseline-signaling state of the aspartate chemoreceptor (Tar) and that Tyr-210 plays an auxiliary role in this control...
  3. Mello B, Tu Y. Effects of adaptation in maintaining high sensitivity over a wide range of backgrounds for Escherichia coli chemotaxis. Biophys J. 2007;92:2329-37 pubmed
    ..A lower bound on the number of Tar receptor dimers (Na) in the complex Na>approximately 6 is obtained from the measured sensitivity...
  4. Homma M, Shiomi D, Homma M, Kawagishi I. Attractant binding alters arrangement of chemoreceptor dimers within its cluster at a cell pole. Proc Natl Acad Sci U S A. 2004;101:3462-7 pubmed
    ..using in vivo disulfide crosslinking assays, we examined an interdimer interaction of the aspartate chemoreceptor (Tar)...
  5. Shimizu T, Le Novère N, Levin M, Beavil A, Sutton B, Bray D. Molecular model of a lattice of signalling proteins involved in bacterial chemotaxis. Nat Cell Biol. 2000;2:792-6 pubmed
    ..This structure creates separate compartments for adaptation and downstream signalling, and indicates a possible basis for the spread of activity within the cluster. ..
  6. Li G, Weis R. Covalent modification regulates ligand binding to receptor complexes in the chemosensory system of Escherichia coli. Cell. 2000;100:357-65 pubmed
    ..Also, the finding that a subsaturating serine concentration accelerates active receptor-kinase complex assembly implies that the assembly/disassembly process may also contribute to kinase regulation. ..
  7. Keymer J, Endres R, Skoge M, Meir Y, Wingreen N. Chemosensing in Escherichia coli: two regimes of two-state receptors. Proc Natl Acad Sci U S A. 2006;103:1786-91 pubmed
    ..e., high Hill coefficient. For homogeneous receptors, we predict an observable transition between regime I and regime II with increasing receptor methylation or amidation. ..
  8. Vaknin A, Berg H. Osmotic stress mechanically perturbs chemoreceptors in Escherichia coli. Proc Natl Acad Sci U S A. 2006;103:592-6 pubmed
    ..Thus, changes in homodimer spacing and/or orientation appear to initiate osmotactic signaling. ..
  9. Shiomi D, Banno S, Homma M, Kawagishi I. Stabilization of polar localization of a chemoreceptor via its covalent modifications and its communication with a different chemoreceptor. J Bacteriol. 2005;187:7647-54 pubmed
    ..we examined the effect of receptor covalent modification on the polar localization of the aspartate chemoreceptor Tar fused to green fluorescent protein (GFP)...
  10. Vaknin A, Berg H. Physical responses of bacterial chemoreceptors. J Mol Biol. 2007;366:1416-23 pubmed
    ..Comparison with responses in kinase-activity indicated that higher-order interactions are dominant in receptor clusters. ..
  11. Endres R, Wingreen N. Precise adaptation in bacterial chemotaxis through "assistance neighborhoods". Proc Natl Acad Sci U S A. 2006;103:13040-4 pubmed
    ..We predict two limits of precise adaptation at large attractant concentrations: Either receptors reach full methylation and turn off, or receptors become saturated and cease to respond to attractant but retain their adapted activity. ..
  12. Mao H, Cremer P, Manson M. A sensitive, versatile microfluidic assay for bacterial chemotaxis. Proc Natl Acad Sci U S A. 2003;100:5449-54 pubmed
    ..A surprising discovery was that L-leucine is sensed by Tar as an attractant at low concentrations and by Tsr as a repellent at higher concentrations...
  13. Liberman L, Berg H, Sourjik V. Effect of chemoreceptor modification on assembly and activity of the receptor-kinase complex in Escherichia coli. J Bacteriol. 2004;186:6643-6 pubmed
    ..Thus, changes in receptor activity do not appear to be mediated by changes in receptor-kinase assembly. ..
  14. Mello B, Tu Y. An allosteric model for heterogeneous receptor complexes: understanding bacterial chemotaxis responses to multiple stimuli. Proc Natl Acad Sci U S A. 2005;102:17354-9 pubmed
    ..It should also be useful for studying the functions of other heterogeneous receptor complexes. ..
  15. Khan S, Spudich J, McCray J, Trentham D. Chemotactic signal integration in bacteria. Proc Natl Acad Sci U S A. 1995;92:9757-61 pubmed
    ..Signaling from Tar and Tsr, two receptors that sense amino acids and pH, was studied...
  16. Zhang Y, Gardina P, Kuebler A, Kang H, Christopher J, Manson M. Model of maltose-binding protein/chemoreceptor complex supports intrasubunit signaling mechanism. Proc Natl Acad Sci U S A. 1999;96:939-44 pubmed
    The Tar protein of Escherichia coli is unique among known bacterial chemoreceptors in that it generates additive responses to two very disparate ligands, aspartate and maltose...
  17. Lai W, Peach M, Lybrand T, Hazelbauer G. Diagnostic cross-linking of paired cysteine pairs demonstrates homologous structures for two chemoreceptor domains with low sequence identity. Protein Sci. 2006;15:94-101 pubmed
    ..The only structure determined is for the periplasmic domain of chemoreceptor Tar from Salmonella and Escherichia coli...
  18. Tajima H, Imada K, Sakuma M, Hattori F, Nara T, Kamo N, et al. Ligand specificity determined by differentially arranged common ligand-binding residues in bacterial amino acid chemoreceptors Tsr and Tar. J Biol Chem. 2011;286:42200-10 pubmed publisher
    Escherichia coli has closely related amino acid chemoreceptors with distinct ligand specificity, Tar for l-aspartate and Tsr for l-serine...
  19. Sal Man N, Gerber D, Shai Y. The composition rather than position of polar residues (QxxS) drives aspartate receptor transmembrane domain dimerization in vivo. Biochemistry. 2004;43:2309-13 pubmed
    ..For this purpose, we used the TM domain of the Escherichia coli aspartate receptor (Tar) and 10 single and double mutants...
  20. Benov L, Fridovich I. Escherichia coli exhibits negative chemotaxis in gradients of hydrogen peroxide, hypochlorite, and N-chlorotaurine: products of the respiratory burst of phagocytic cells. Proc Natl Acad Sci U S A. 1996;93:4999-5002 pubmed
    ..Hypochlorite and N-chlorotaurine were also strongly repellent. Chemotaxis down gradients of H2O2, OCl-, and N-chlorotaurine may contribute to the survival of commensal or pathogenic microorganisms. ..
  21. Slocum M, Parkinson J. Genetics of methyl-accepting chemotaxis proteins in Escherichia coli: organization of the tar region. J Bacteriol. 1983;155:565-77 pubmed
    The tar locus of Escherichia coli specifies one of the major species of methyl-accepting proteins involved in the chemotactic behavior of this organism...
  22. Lane M, Lloyd A, Markyvech T, Hagan E, Mobley H. Uropathogenic Escherichia coli strains generally lack functional Trg and Tap chemoreceptors found in the majority of E. coli strains strictly residing in the gut. J Bacteriol. 2006;188:5618-25 pubmed
    The prevalence and function of four chemoreceptors, Tsr, Tar, Trg, and Tap, were determined for a collection of uropathogenic, fecal-commensal, and diarrheagenic Escherichia coli strains...
  23. 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
  24. Falke J, Bass R, Butler S, Chervitz S, Danielson M. The two-component signaling pathway of bacterial chemotaxis: a molecular view of signal transduction by receptors, kinases, and adaptation enzymes. Annu Rev Cell Dev Biol. 1997;13:457-512 pubmed
    ..Overall, the chemosensory pathway and the propulsion system it regulates provide an ideal system in which to probe molecular principles underlying complex cellular signaling and behavior. ..
  25. Lai W, Hazelbauer G. Carboxyl-terminal extensions beyond the conserved pentapeptide reduce rates of chemoreceptor adaptational modification. J Bacteriol. 2005;187:5115-21 pubmed
    ..of both enzyme activities? To address these questions, we created forms of high-abundance receptor Tsr or Tar carrying one, six, or eight additional amino acids extending beyond the pentapeptide at their carboxyl termini and ..
  26. Bowie J, Pakula A, Simon M. The three-dimensional structure of the aspartate receptor from Escherichia coli. Acta Crystallogr D Biol Crystallogr. 1995;51:145-54 pubmed
    ..The inability of the receptor from Salmonella typhimurium to respond to maltose may, therefore, be because of differences in amino acids located on the binding surface rather than structural differences. ..
  27. Bartelli N, Hazelbauer G. Direct evidence that the carboxyl-terminal sequence of a bacterial chemoreceptor is an unstructured linker and enzyme tether. Protein Sci. 2011;20:1856-66 pubmed publisher
    ..coli chemoreceptor Tar. Beginning ? 35 residues from the carboxyl terminus and continuing to the end of the protein, spectra of spin-..
  28. Chowdhury A, Feng R, Tong Q, Zhang Y, Xie X. Mistic and TarCF as fusion protein partners for functional expression of the cannabinoid receptor 2 in Escherichia coli. Protein Expr Purif. 2012;83:128-34 pubmed publisher
    ..expression enhancer at the N-terminal, and TarCF, a C-terminal fragment of the bacterial chemosensory transducer Tar at the C-terminal of the CB2 open reading frame region...
  29. Antommattei F, Munzner J, Weis R. Ligand-specific activation of Escherichia coli chemoreceptor transmethylation. J Bacteriol. 2004;186:7556-63 pubmed
    ..g., either the full-length aspartate or serine receptor (Tar or Tsr)...
  30. Gosink K, Burón Barral M, Parkinson J. Signaling interactions between the aerotaxis transducer Aer and heterologous chemoreceptors in Escherichia coli. J Bacteriol. 2006;188:3487-93 pubmed
    ..We obtained evidence for interactions between Aer and the high-abundance aspartate (Tar) and serine (Tsr) receptors...
  31. Springer M, Goy M, Adler J. Sensory transduction in Escherichia coli: two complementary pathways of information processing that involve methylated proteins. Proc Natl Acad Sci U S A. 1977;74:3312-6 pubmed
    The properties of two classes of behavioral mutants of Escherichia coli (called tsr and tar) are described...
  32. Bartelli N, Hazelbauer G. Bacterial Chemoreceptor Dynamics: Helical Stability in the Cytoplasmic Domain Varies with Functional Segment and Adaptational Modification. J Mol Biol. 2016;428:3789-804 pubmed publisher
    ..physiological conditions, the mobility of helical backbones in the cytoplasmic domain of intact chemoreceptor Tar homodimers inserted into lipid bilayers of Nanodiscs...
  33. Falke J, Koshland D. Global flexibility in a sensory receptor: a site-directed cross-linking approach. Science. 1987;237:1596-600 pubmed
    ..The results indicate that the receptor oligomer has a flexible, dynamic structure which undergoes a global change upon aspartate binding. ..
  34. Gardina P, Bormans A, Hawkins M, Meeker J, Manson M. Maltose-binding protein interacts simultaneously and asymmetrically with both subunits of the Tar chemoreceptor. Mol Microbiol. 1997;23:1181-91 pubmed
    The Tar chemotactic signal transducer of Escherichia coli mediates attractant responses to L-aspartate and to maltose. Aspartate binds across the subunit interface of the periplasmic receptor domain of a Tar homodimer...
  35. Yeh J, Biemann H, Pandit J, Koshland D, Kim S. The three-dimensional structure of the ligand-binding domain of a wild-type bacterial chemotaxis receptor. Structural comparison to the cross-linked mutant forms and conformational changes upon ligand binding. J Biol Chem. 1993;268:9787-92 pubmed
    ..4) The nature and magnitude of the aspartate-induced conformational changes in the non-cross-linked wild-type structures are very similar to those of the cross-linked structures. ..
  36. Zhang Y, Conway C, Rosato M, Suh Y, Manson M. Maltose chemotaxis involves residues in the N-terminal and C-terminal domains on the same face of maltose-binding protein. J Biol Chem. 1992;267:22813-20 pubmed
    ..It interacts with the Tar chemotactic signal transducer and the integral cytoplasmic-membrane components (the MalF and MalG proteins) of the ..
  37. Greenfield D, McEvoy A, Shroff H, Crooks G, Wingreen N, Betzig E, et al. Self-organization of the Escherichia coli chemotaxis network imaged with super-resolution light microscopy. PLoS Biol. 2009;7:e1000137 pubmed publisher
    ..localization microscopy (PALM) to map the cellular locations of three proteins central to bacterial chemotaxis (the Tar receptor, CheY, and CheW) with a precision of 15 nm...
  38. 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. ..
  39. Albert R, Chiu Y, Othmer H. Dynamic receptor team formation can explain the high signal transduction gain in Escherichia coli. Biophys J. 2004;86:2650-9 pubmed
    ..Only recently has a source of gain in the signal transduction network been identified experimentally, and here we present a mathematical model based on dynamic assembly of receptor teams that can explain this observation. ..
  40. Ames P, Parkinson J. Conformational suppression of inter-receptor signaling defects. Proc Natl Acad Sci U S A. 2006;103:9292-7 pubmed
    ..We isolated and characterized mutations (designated Tar()) in the aspartate chemoreceptor that restored function to Tsr* receptors...
  41. Pham H, Parkinson J. Phenol sensing by Escherichia coli chemoreceptors: a nonclassical mechanism. J Bacteriol. 2011;193:6597-604 pubmed publisher
    The four transmembrane chemoreceptors of Escherichia coli sense phenol as either an attractant (Tar) or a repellent (Tap, Trg, and Tsr)...
  42. Wright S, Walia B, Parkinson J, Khan S. Differential activation of Escherichia coli chemoreceptors by blue-light stimuli. J Bacteriol. 2006;188:3962-71 pubmed
    ..of deletion mutants revealed a specific requirement for either the aerotaxis receptor Aer or the chemoreceptor Tar but not the Tar homolog Tsr...
  43. Kanchan K, Linder J, Winkler K, Hantke K, Schultz A, Schultz J. Transmembrane signaling in chimeras of the Escherichia coli aspartate and serine chemotaxis receptors and bacterial class III adenylyl cyclases. J Biol Chem. 2010;285:2090-9 pubmed publisher
    The Escherichia coli chemoreceptors for serine (Tsr) and aspartate (Tar) and several bacterial class III adenylyl cyclases (ACs) share a common molecular architecture; that is, a membrane anchor that is linked via a cytoplasmic HAMP ..
  44. Manson M, Boos W, Bassford P, Rasmussen B. Dependence of maltose transport and chemotaxis on the amount of maltose-binding protein. J Biol Chem. 1985;260:9727-33 pubmed
    ..with two sets of cytoplasmic membrane proteins, the MalFGK transport complex and the chemotactic signal transducer Tar. MBP is present at high concentrations, on the order of 1 mM, in the periplasm of maltose-induced or malTc ..
  45. Wolanin P, Baker M, Francis N, Thomas D, Derosier D, Stock J. Self-assembly of receptor/signaling complexes in bacterial chemotaxis. Proc Natl Acad Sci U S A. 2006;103:14313-8 pubmed
    ..Fusing the cytoplasmic domain of the aspartate receptor, Tar, to a leucine zipper dimerization domain produces a hybrid, lzTar(C), that forms soluble complexes with CheA and ..
  46. Li M, Hazelbauer G. Adaptational assistance in clusters of bacterial chemoreceptors. Mol Microbiol. 2005;56:1617-26 pubmed
    ..Using membrane vesicles containing both high-abundance receptor Tar and low-abundance receptor Trg, we observed effective assistance in vitro for all three adaptational modifications: ..
  47. Levit M, Liu Y, Stock J. Stimulus response coupling in bacterial chemotaxis: receptor dimers in signalling arrays. Mol Microbiol. 1998;30:459-66 pubmed
    ..Results with receptor chimeras as well as findings with tyrosine kinase receptors suggest that this mechanism may represent a common theme in membrane receptor function. ..
  48. Massazza D, Parkinson J, Studdert C. Cross-linking evidence for motional constraints within chemoreceptor trimers of dimers. Biochemistry. 2011;50:820-7 pubmed publisher
    ..define six different levels along the cytoplasmic signaling domains of the aspartate and serine chemoreceptors, Tar and Tsr, respectively...
  49. Adase C, Draheim R, Rueda G, Desai R, Manson M. Residues at the cytoplasmic end of transmembrane helix 2 determine the signal output of the TarEc chemoreceptor. Biochemistry. 2013;52:2729-38 pubmed publisher
    ..and communication between the periplasmic and cytoplasmic domains of the Escherichia coli aspartate chemoreceptor Tar(Ec) are both strongly influenced by residues at the C-terminus of transmembrane helix 2 (TM2)...
  50. Mizuno T, Imae Y. Conditional inversion of the thermoresponse in Escherichia coli. J Bacteriol. 1984;159:360-7 pubmed
    ..to attractants such as L-aspartate and maltose, which are specific to another methyl-accepting chemotaxis protein, Tar protein, the direction of the thermoresponse was found to be inverted; a temperature increase induced tumbling and ..
  51. Salman H, Libchaber A. A concentration-dependent switch in the bacterial response to temperature. Nat Cell Biol. 2007;9:1098-100 pubmed
    ..At high bacterial concentration, the switch is reinforced by an inversion of the Tar/Tsr expression ratio.
  52. Lynch B, Koshland D. Disulfide cross-linking studies of the transmembrane regions of the aspartate sensory receptor of Escherichia coli. Proc Natl Acad Sci U S A. 1991;88:10402-6 pubmed
    ..These targeted disulfide cross-links can be used to reveal structural and dynamic aspects of protein function. ..
  53. Biemann H, Koshland D. Aspartate receptors of Escherichia coli and Salmonella typhimurium bind ligand with negative and half-of-the-sites cooperativity. Biochemistry. 1994;33:629-34 pubmed
    ..Comparison of the X-ray crystal structure of the ligand binding domain with and without bound aspartate revealed ligand-induced conformational changes that explain the two examples of negative cooperativity. ..
  54. Ridgway H, Silverman M, Simon M. Localization of proteins controlling motility and chemotaxis in Escherichia coli. J Bacteriol. 1977;132:657-65 pubmed
    ..The motA, motB, cheM, and cheD gene products were found to be confined exclusively to the inner cytoplasmic membrane fraction, whereas ..
  55. Manson M, Kossmann M. Mutations in tar suppress defects in maltose chemotaxis caused by specific malE mutations. J Bacteriol. 1986;165:34-40 pubmed
    ..Maltose-loaded MBP is thought to initiate a chemotactic response by binding to the tar gene product, the signal transducer Tar, which is also the aspartate chemoreceptor...
  56. Dahl M, Manson M. Interspecific reconstitution of maltose transport and chemotaxis in Escherichia coli with maltose-binding protein from various enteric bacteria. J Bacteriol. 1985;164:1057-63 pubmed
    ..It is also the maltose chemoreceptor, in which capacity it interacts with the signal transducer Tar (taxis to aspartate and some repellents)...
  57. Borkovich K, Alex L, Simon M. Attenuation of sensory receptor signaling by covalent modification. Proc Natl Acad Sci U S A. 1992;89:6756-60 pubmed
    The Tar receptor is a transmembrane protein that regulates bacterial chemotaxis in response to changes in the level of aspartic acid in the medium...
  58. Weerasuriya S, Schneider B, Manson M. Chimeric chemoreceptors in Escherichia coli: signaling properties of Tar-Tap and Tap-Tar hybrids. J Bacteriol. 1998;180:914-20 pubmed
    ..Tap is a low-abundance receptor. It is present in 5- to 10-fold-fewer copies than high-abundance receptors like Tar and Tsr...
  59. Barak R, Eisenbach M. Correlation between phosphorylation of the chemotaxis protein CheY and its activity at the flagellar motor. Biochemistry. 1992;31:1821-6 pubmed
    ..This increase in activity requires additional cytoplasmic constituents, the identity of which is not yet known. ..
  60. Botelho S, Enquist K, von Heijne G, Draheim R. Differential repositioning of the second transmembrane helices from E. coli Tar and EnvZ upon moving the flanking aromatic residues. Biochim Biophys Acta. 2015;1848:615-21 pubmed publisher
    ..within bacterial receptors, has been previously shown to modulate signal output from the aspartate chemoreceptor (Tar) and the major osmosensor EnvZ of Escherichia coli...
  61. Yang Y, Sourjik V. Opposite responses by different chemoreceptors set a tunable preference point in Escherichia coli pH taxis. Mol Microbiol. 2012;86:1482-9 pubmed publisher
    ..Such inversion is enabled by opposing pH sensing by the two major chemoreceptors, Tar and Tsr, such that the relative strength of the response is modulated by adaptive receptor methylation...
  62. Sal Man N, Shai Y. Arginine mutations within a transmembrane domain of Tar, an Escherichia coli aspartate receptor, can drive homodimer dissociation and heterodimer association in vivo. Biochem J. 2005;385:29-36 pubmed
    ..To address this issue, we employed the N-terminal TM domain of the aspartate receptor (Tar-1) as a dimerization model system...
  63. Hulko M, Berndt F, Gruber M, Linder J, Truffault V, Schultz A, et al. The HAMP domain structure implies helix rotation in transmembrane signaling. Cell. 2006;126:929-40 pubmed publisher
    ..coli chemotaxis receptor. Structural and functional studies show that the equilibrium between the two forms is dependent on the side-chain size of residue 291, which is alanine in the wild-type protein...
  64. Gardina P, Manson M. Attractant signaling by an aspartate chemoreceptor dimer with a single cytoplasmic domain. Science. 1996;274:425-6 pubmed
    ..The aspartate receptor (Tar) is a homodimer, and oligomerized cytoplasmic domains stimulate CheA activity much more than monomers do in vitro...
  65. Bass R, Miller A, Gloor S, Falke J. The PICM chemical scanning method for identifying domain-domain and protein-protein interfaces: applications to the core signaling complex of E. coli chemotaxis. Methods Enzymol. 2007;423:3-24 pubmed
    ..typhimurium chemotaxis pathway, where it has mapped out essential docking surfaces on transmembrane chemoreceptor (Tar) and histidine kinase (CheA) components (Bass and Falke, 1998; Mehan et al., 2003; Miller et al., 2006)...
  66. Li M, Hazelbauer G. The carboxyl-terminal linker is important for chemoreceptor function. Mol Microbiol. 2006;60:469-79 pubmed
    ..We created nested deletions from the distal end of this linker in chemoreceptor Tar. Chemotaxis was eliminated by deletion of 20-40 residues and reduced by shorter deletions...
  67. Ames P, Parkinson J. Phenotypic suppression methods for analyzing intra- and inter-molecular signaling interactions of chemoreceptors. Methods Enzymol. 2007;423:436-57 pubmed
    ..The suppression patterns exhibit allele-specificity with respect to the compensatory residue positions and amino acid side chains, a hallmark of stereospecific protein-protein interactions. ..
  68. Dahl M, Boos W, Manson M. Evolution of chemotactic-signal transducers in enteric bacteria. J Bacteriol. 1989;171:2361-71 pubmed
    ..aerogenes complements the defect in aspartate taxis, but not the defect in maltose taxis, of an E. coli tar mutant. The sequence was determined for 5 kilobases of E...
  69. Khan S, Trentham D. Biphasic excitation by leucine in Escherichia coli chemotaxis. J Bacteriol. 2004;186:588-92 pubmed
    ..by photolysis of inert derivatives) triggered swim or tumble responses in Escherichia coli mutants lacking Tsr or Tar, respectively. Wild-type E...
  70. Goldberg S, Derr P, Degrado W, Goulian M. Engineered single- and multi-cell chemotaxis pathways in E. coli. Mol Syst Biol. 2009;5:283 pubmed publisher
    ..The result effectively introduces a logical 'AND' into the system so that the population only swims towards the combined gradients of two attractants. ..
  71. Yamamoto K, Macnab R, Imae Y. Repellent response functions of the Trg and Tap chemoreceptors of Escherichia coli. J Bacteriol. 1990;172:383-8 pubmed
    ..In the absence of all four known methyl-accepting chemoreceptors (Tar, Tsr, Trg, and Tap), cells showed no response to phenol...
  72. Zhu Y, Inouye M. The HAMP linker in histidine kinase dimeric receptors is critical for symmetric transmembrane signal transduction. J Biol Chem. 2004;279:48152-8 pubmed
    ..Here, by in vivo complementation experiments with Tar-EnvZ hybrid receptor mutants in which the HAMP linker forms a heterodimer with Tar and EnvZ-type subunits, we found ..
  73. Ward S, Delgado A, Gunsalus R, Manson M. A NarX-Tar chimera mediates repellent chemotaxis to nitrate and nitrite. Mol Microbiol. 2002;44:709-19 pubmed
    ..transmembrane and linker domains of the NarX sensor kinase to the signalling and adaptation domains of the Tar chemoreceptor of Escherichia coli mediates repellent responses to nitrate and nitrite...
  74. Gardina P, Bormans A, Manson M. A mechanism for simultaneous sensing of aspartate and maltose by the Tar chemoreceptor of Escherichia coli. Mol Microbiol. 1998;29:1147-54 pubmed
    The Tar chemoreceptor of Escherichia coli exhibits partial sensory additivity. Tar can mediate simultaneous responses to two disparate ligands, aspartate and substrate-loaded maltose-binding protein (MBP)...
  75. Shiomi D, Okumura H, Homma M, Kawagishi I. The aspartate chemoreceptor Tar is effectively methylated by binding to the methyltransferase mainly through hydrophobic interaction. Mol Microbiol. 2000;36:132-40 pubmed
    ..In this study, we carried out a systematic mutagenesis of the pentapeptide sequence of Tar. Receptor methylation and adaptation were severely impaired by the alanine substitution of residue W550 and, to a ..
  76. Wang E, Mowry K, Clegg D, Koshland D. Tandem duplication and multiple functions of a receptor gene in bacterial chemotaxis. J Biol Chem. 1982;257:4673-6 pubmed
    The aspartate receptor in bacterial sensing, previously identified with the tar gene, has been shown to be duplicated in tandem in Escherichia coli...
  77. Greenswag A, Li X, Borbat P, Samanta D, Watts K, Freed J, et al. Preformed Soluble Chemoreceptor Trimers That Mimic Cellular Assembly States and Activate CheA Autophosphorylation. Biochemistry. 2015;54:3454-68 pubmed publisher
    ..engineered chemoreceptor cytoplasmic kinase-control modules (KCMs) based on the Escherichia coli aspartate receptor Tar that are covalently fused and trimerized by a foldon domain (Tar(FO))...