Search tips
Search criteria 


Logo of jbacterPermissionsJournals.ASM.orgJournalJB ArticleJournal InfoAuthorsReviewers
J Bacteriol. 1990 December; 172(12): 7179–7187.
PMCID: PMC210843

Effects of glutamines and glutamates at sites of covalent modification of a methyl-accepting transducer.


Chemotactic transducer proteins of Escherichia coli contain four or five methyl-accepting glutamates that are crucial for sensory adaptation and gradient sensing. Two residues arise from posttranslational deamidation of glutamines to yield methyl-accepting glutamates. We addressed the significance of this arrangement by creating two mutated trg genes: trg(5E), coding for a transducer in which all five modification sites were synthesized as glutamates, and trg(5Q), in which all five were glutamines. We found that the normal (3E,2Q) configuration was not an absolute requirement for synthesis, assembly, or stable maintenance of transducers. Both mutant proteins were methylated, although Trg(5Q) had a reduced number of methyl-accepting sites because two glutamines at adjacent residues were blocked for deamidation and thus could not become methyl-accepting glutamates. The glutamine-glutamate balance had striking effects on signaling state. Trg(5E) was in a strong counterclockwise signaling configuration, and Trg(5Q) was in a strong clockwise signaling induced by ligand binding, and alanines substituted at modification sites had an intermediate effect. Chemotactic migration by growing cells containing trg(5E) or trg(5Q) exhibited reduced effectiveness, probably reflecting perturbations of the counterclockwise/clockwise ratio caused by newly synthesized transducers not modified rapidly enough to produce a balanced signaling state during growth. These defects were evident for cells in which other transducers were not available to contribute to balanced signaling or were present at lower levels than the mutant proteins.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (2.5M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Bollinger J, Park C, Harayama S, Hazelbauer GL. Structure of the Trg protein: Homologies with and differences from other sensory transducers of Escherichia coli. Proc Natl Acad Sci U S A. 1984 Jun;81(11):3287–3291. [PubMed]
  • Borkovich KA, Kaplan N, Hess JF, Simon MI. Transmembrane signal transduction in bacterial chemotaxis involves ligand-dependent activation of phosphate group transfer. Proc Natl Acad Sci U S A. 1989 Feb;86(4):1208–1212. [PubMed]
  • Boyd A, Simon MI. Multiple electrophoretic forms of methyl-accepting chemotaxis proteins generated by stimulus-elicited methylation in Escherichia coli. J Bacteriol. 1980 Aug;143(2):809–815. [PMC free article] [PubMed]
  • Burrows GG, Newcomer ME, Hazelbauer GL. Purification of receptor protein Trg by exploiting a property common to chemotactic transducers of Escherichia coli. J Biol Chem. 1989 Oct 15;264(29):17309–17315. [PubMed]
  • Chelsky D, Dahlquist FW. Structural studies of methyl-accepting chemotaxis proteins of Escherichia coli: evidence for multiple methylation sites. Proc Natl Acad Sci U S A. 1980 May;77(5):2434–2438. [PubMed]
  • Clarke S, Koshland DE., Jr Membrane receptors for aspartate and serine in bacterial chemotaxis. J Biol Chem. 1979 Oct 10;254(19):9695–9702. [PubMed]
  • DeFranco AL, Koshland DE., Jr Multiple methylation in processing of sensory signals during bacterial chemotaxis. Proc Natl Acad Sci U S A. 1980 May;77(5):2429–2433. [PubMed]
  • Engström P, Hazelbauer GL. Multiple methylation of methyl-accepting chemotaxis proteins during adaptation of E. coli to chemical stimuli. Cell. 1980 May;20(1):165–171. [PubMed]
  • Hazelbauer GL. The bacterial chemosensory system. Can J Microbiol. 1988 Apr;34(4):466–474. [PubMed]
  • Hazelbauer GL, Engström P. Multiple forms of methyl-accepting chemotaxis proteins distinguished by a factor in addition to multiple methylation. J Bacteriol. 1981 Jan;145(1):35–42. [PMC free article] [PubMed]
  • Hazelbauer GL, Harayama S. Mutants in transmission of chemotactic signals from two independent receptors of E. coli. Cell. 1979 Mar;16(3):617–625. [PubMed]
  • Hazelbauer GL, Harayama S. Sensory transduction in bacterial chemotaxis. Int Rev Cytol. 1983;81:33–70. [PubMed]
  • Hazelbauer GL, Park C, Nowlin DM. Adaptational "crosstalk" and the crucial role of methylation in chemotactic migration by Escherichia coli. Proc Natl Acad Sci U S A. 1989 Mar;86(5):1448–1452. [PubMed]
  • Imae Y, Mizuno T, Maeda K. Chemosensory and thermosensory excitation in adaptation-deficient mutants of Escherichia coli. J Bacteriol. 1984 Jul;159(1):368–374. [PMC free article] [PubMed]
  • Kehry MR, Bond MW, Hunkapiller MW, Dahlquist FW. Enzymatic deamidation of methyl-accepting chemotaxis proteins in Escherichia coli catalyzed by the cheB gene product. Proc Natl Acad Sci U S A. 1983 Jun;80(12):3599–3603. [PubMed]
  • Kehry MR, Dahlquist FW. Adaptation in bacterial chemotaxis: CheB-dependent modification permits additional methylations of sensory transducer proteins. Cell. 1982 Jul;29(3):761–772. [PubMed]
  • Kehry MR, Dahlquist FW. The methyl-accepting chemotaxis proteins of Escherichia coli. Identification of the multiple methylation sites on methyl-accepting chemotaxis protein I. J Biol Chem. 1982 Sep 10;257(17):10378–10386. [PubMed]
  • Kehry MR, Engström P, Dahlquist FW, Hazelbauer GL. Multiple covalent modifications of Trg, a sensory transducer of Escherichia coli. J Biol Chem. 1983 Apr 25;258(8):5050–5055. [PubMed]
  • Kondoh H, Ball CB, Adler J. Identification of a methyl-accepting chemotaxis protein for the ribose and galactose chemoreceptors of Escherichia coli. Proc Natl Acad Sci U S A. 1979 Jan;76(1):260–264. [PubMed]
  • Manson MD, Blank V, Brade G, Higgins CF. Peptide chemotaxis in E. coli involves the Tap signal transducer and the dipeptide permease. Nature. 1986 May 15;321(6067):253–256. [PubMed]
  • Nowlin DM, Bollinger J, Hazelbauer GL. Sites of covalent modification in Trg, a sensory transducer of Escherichia coli. J Biol Chem. 1987 May 5;262(13):6039–6045. [PubMed]
  • Nowlin DM, Bollinger J, Hazelbauer GL. Site-directed mutations altering methyl-accepting residues of a sensory transducer protein. Proteins. 1988;3(2):102–112. [PubMed]
  • Park C, Hazelbauer GL. Mutations specifically affecting ligand interaction of the Trg chemosensory transducer. J Bacteriol. 1986 Jul;167(1):101–109. [PMC free article] [PubMed]
  • Parkinson JS, Houts SE. Isolation and behavior of Escherichia coli deletion mutants lacking chemotaxis functions. J Bacteriol. 1982 Jul;151(1):106–113. [PMC free article] [PubMed]
  • Rollins C, Dahlquist FW. The methyl-accepting chemotaxis proteins of E. coli: a repellent-stimulated, covalent modification, distinct from methylation. Cell. 1981 Aug;25(2):333–340. [PubMed]
  • Sager BM, Sekelsky JJ, Matsumura P, Adler J. Use of a computer to assay motility in bacteria. Anal Biochem. 1988 Sep;173(2):271–277. [PubMed]
  • Segall JE, Block SM, Berg HC. Temporal comparisons in bacterial chemotaxis. Proc Natl Acad Sci U S A. 1986 Dec;83(23):8987–8991. [PubMed]
  • Sherris D, Parkinson JS. Posttranslational processing of methyl-accepting chemotaxis proteins in Escherichia coli. Proc Natl Acad Sci U S A. 1981 Oct;78(10):6051–6055. [PubMed]
  • Snyder MA, Stock JB, Koshland DE., Jr Carboxylmethyl esterase of bacterial chemotaxis. Methods Enzymol. 1984;106:321–330. [PubMed]
  • Springer MS, Goy MF, Adler J. Protein methylation in behavioural control mechanisms and in signal transduction. Nature. 1979 Jul 26;280(5720):279–284. [PubMed]
  • Stock JB, Clarke S, Koshland DE., Jr The protein carboxylmethyltransferase involved in Escherichia coli and Salmonella typhimurium chemotaxis. Methods Enzymol. 1984;106:310–321. [PubMed]
  • Terwilliger TC, Wang JY, Koshland DE., Jr Kinetics of receptor modification. The multiply methylated aspartate receptors involved in bacterial chemotaxis. J Biol Chem. 1986 Aug 15;261(23):10814–10820. [PubMed]
  • Weis RM, Koshland DE., Jr Reversible receptor methylation is essential for normal chemotaxis of Escherichia coli in gradients of aspartic acid. Proc Natl Acad Sci U S A. 1988 Jan;85(1):83–87. [PubMed]
  • Yamamoto K, Macnab RM, Imae Y. Repellent response functions of the Trg and Tap chemoreceptors of Escherichia coli. J Bacteriol. 1990 Jan;172(1):383–388. [PMC free article] [PubMed]
  • Yonekawa H, Hayashi H, Parkinson JS. Requirement of the cheB function for sensory adaptation in Escherichia coli. J Bacteriol. 1983 Dec;156(3):1228–1235. [PMC free article] [PubMed]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)