To improve security and privacy, we are moving our web pages and services from HTTP to HTTPS.
To give users of web services time to transition to HTTPS, we will support separate HTTP and HTTPS services until the end of 2017.
From January 2018 most HTTP traffic will be automatically redirected to HTTPS. [more...]
View this page in https
PROSITE documentation PDOC00465 [for PROSITE entry PS50111]

Bacterial chemotaxis sensory transducers signature and profile





Description

Bacterial chemotactic-signal transducers [1,2] are proteins that respond to changes in the concentration of attractants and repellents in the environment, and transduce a signal from the outside to the inside of the cell. These proteins undergo two covalent modifications: deamidation and reversible methylation. Attractants increase the level of methylation while repellents decrease it. The methyl groups are added by the methyl-transferase cheR and are removed by the methylesterase cheB.

In Escherichia coli and related bacteria, there are four different chemotactic transducers:

  • tsr, responsible for taxis to the attractants L-serine and related amino acids and away from the repellents leucine, indole, and weak acids.
  • tar, responsible for taxis to the attractants L-aspartate and related amino and dicarboxylic acids. Also mediates taxis to the attractant maltose via an interaction with the periplasmic maltose-binding protein. Mediates taxis away from the repellents cobalt and nickel.
  • trg, responsible for taxis to ribose and galactose via an interaction with the periplasmic ribose- or galactose-binding proteins.
  • tap, responsible for taxis towards dipeptides via an interaction with the periplasmic dipeptide-binding protein.

In Enterobacter aerogenes [3] there are at least two different chemotactic transducers:

  • tsr, responsible for taxis to the attractant L-serine.
  • tas, responsible for taxis to the attractant L-aspartate.

In Salmonella typhimurium [4], in addition to tar, there is:

  • tcp, responsible for taxis to the attractant citrate.

All these proteins are composed of the same structural domains: a N-terminal region that resembles a signal peptide, but which is not removed from the mature protein and serves as a membrane-spanning region; a periplasmic domain of about 160 amino acids that forms the receptor domain; a second transmembrane region and finally a C-terminal cytoplasmic domain of about 300 amino acids which contains the methylation sites.

The methyl-accepting sites are specific glutamate residues (some of these sites are translated as glutamine but are irreversibly deamidated by cheB). They are clustered in two regions of the cytoplasmic domain [5]. As a signature pattern we have selected the first of these two regions.

Last update:

September 2002 / text revised; profile added.

Technical section

PROSITE methods (with tools and information) covered by this documentation:

CHEMOTAXIS_TRANSDUC_2, PS50111; Bacterial chemotaxis sensory transducers domain profile  (MATRIX)

CHEMOTAXIS_TRANSDUC_1, PS00538; Bacterial chemotaxis sensory transducers signature  (PATTERN)


References

1AuthorsStewart R.C., Dahlquist F.W.
SourceChem. Rev. 87:997-1025(1987).

2AuthorsHazelbauer G.L.
TitleThe bacterial chemosensory system.
SourceCan. J. Microbiol. 34:466-474(1988).
PubMed ID3052756

3AuthorsDahl M.K., Boos W., Manson M.D.
TitleEvolution of chemotactic-signal transducers in enteric bacteria.
SourceJ. Bacteriol. 171:2361-2371(1989).
PubMed ID2496104

4AuthorsYamamoto K., Imae Y.
TitleCloning and characterization of the Salmonella typhimurium-specific chemoreceptor Tcp for taxis to citrate and from phenol.
SourceProc. Natl. Acad. Sci. U.S.A. 90:217-221(1993).
PubMed ID8419927

5AuthorsRice M.S., Dahlquist F.W.
TitleSites of deamidation and methylation in Tsr, a bacterial chemotaxis sensory transducer.
SourceJ. Biol. Chem. 266:9746-9753(1991).
PubMed ID2033064



PROSITE is copyright. It is produced by the SIB Swiss Institute Bioinformatics. There are no restrictions on its use by non-profit institutions as long as its content is in no way modified. Usage by and for commercial entities requires a license agreement. For information about the licensing scheme send an email to
Prosite License or see: prosite_license.html.

Miscellaneous

View entry in original PROSITE document format
View entry in raw text format (no links)