| Structural highlights
Function
[PCTA_PSEAE] Chemotactic-signal transducers respond to changes in the concentration of attractants and repellents in the environment, transduce a signal from the outside to the inside of the cell, and facilitate sensory adaptation through the variation of the level of methylation. Major receptor that responds to all naturally occurring L-amino acids, except L-Gln and L-Asp. Also involved in repellent responses to trichloroethylene (TCE), chloroform and methylthiocyanate.[1] [2] [3] [4]
Publication Abstract from PubMed
Pseudomonas aeruginosa is an opportunistic pathogen and one of the major model organisms for the study of chemotaxis. The bacterium harbours 26 genes encoding chemoreceptors, most of which have not been annotated with a function. The paralogous chemoreceptors PctA and PctB (Pseudomonas chemotactic transducer A and B) were found to mediate chemotaxis towards L-amino acids. However, the ligand spectrum of the receptors is quite different since the recombinant ligand-binding region (LBR) of PctA binds 17 different L-amino acids whereas that of PctB recognizes only five. To determine the molecular basis underlying this ligand specificity, PctA-LBR and PctB-LBR have been purified and crystals have been produced after pre-incubation with L-Ile and L-Arg, respectively. Initial crystallization conditions have been identified by the counter-diffusion method and X-ray data have been collected at 2.5 A (PctA-LBR bound to L-Ile) and 3.14 A (PctB-LBR bound to L-Arg) resolution. Crystals belonged to space groups P2(1)2(1)2(1) and P3(1)2(1), with unit-cell parameters a = 72.2, b = 78.5, c = 116.6 A and a = b = 111.6, c = 117.4, respectively, for PctA-LBR and PctB-LBR. Molecular-replacement methods will be pursued for structural determination.
Purification, crystallization and preliminary crystallographic analysis of the ligand-binding regions of the PctA and PctB chemoreceptors from Pseudomonas aeruginosa in complex with amino acids.,Rico-Jimenez M, Munoz-Martinez F, Krell T, Gavira JA, Pineda-Molina E Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 Dec;69(Pt 12):1431-5. doi:, 10.1107/S1744309113023592. Epub 2013 Nov 29. PMID:24316847[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Shitashiro M, Tanaka H, Hong CS, Kuroda A, Takiguchi N, Ohtake H, Kato J. Identification of chemosensory proteins for trichloroethylene in Pseudomonas aeruginosa. J Biosci Bioeng. 2005 Apr;99(4):396-402. PMID:16233808 doi:http://dx.doi.org/10.1263/jbb.99.396
- ↑ Rico-Jimenez M, Munoz-Martinez F, Garcia-Fontana C, Fernandez M, Morel B, Ortega A, Ramos JL, Krell T. Paralogous chemoreceptors mediate chemotaxis towards protein amino acids and the non-protein amino acid gamma-aminobutyrate (GABA). Mol Microbiol. 2013 Jun;88(6):1230-43. doi: 10.1111/mmi.12255. Epub 2013 May 22. PMID:23650915 doi:http://dx.doi.org/10.1111/mmi.12255
- ↑ Kuroda A, Kumano T, Taguchi K, Nikata T, Kato J, Ohtake H. Molecular cloning and characterization of a chemotactic transducer gene in Pseudomonas aeruginosa. J Bacteriol. 1995 Dec;177(24):7019-25. PMID:8522505
- ↑ Taguchi K, Fukutomi H, Kuroda A, Kato J, Ohtake H. Genetic identification of chemotactic transducers for amino acids in Pseudomonas aeruginosa. Microbiology. 1997 Oct;143 ( Pt 10):3223-9. PMID:9353923 doi:http://dx.doi.org/10.1099/00221287-143-10-3223
- ↑ Rico-Jimenez M, Munoz-Martinez F, Krell T, Gavira JA, Pineda-Molina E. Purification, crystallization and preliminary crystallographic analysis of the ligand-binding regions of the PctA and PctB chemoreceptors from Pseudomonas aeruginosa in complex with amino acids. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 Dec;69(Pt 12):1431-5. doi:, 10.1107/S1744309113023592. Epub 2013 Nov 29. PMID:24316847 doi:http://dx.doi.org/10.1107/S1744309113023592
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