Escherichia coli K-12 substr. MG1655 Pathway: TorSR Two-Component Signal Transduction System, TMAO dependent
Inferred from experiment

Pathway diagram: TorSR Two-Component Signal Transduction System, TMAO dependent

Diagram Key:

Locations of Mapped Genes:

Schematic showing all replicons, marked with selected genes

Genetic Regulation Schematic

Genetic regulation schematic for TorSR Two-Component Signal Transduction System, TMAO dependent

Superclasses: Signal transduction pathways

In the absence of oxygen E.coli K-12 is able to generate energy using a variety of different substances as terminal electron acceptors. One such substance is trimethylamine N-oxide (TMAO) which, under anaerobic conditions, is reduced to TMA by the action of the periplasmic molybdoprotein TMAO reductase, encoded by the TorCA genes. TorSR is the two-component signal transduction system that controls the cells ability to use TMAO as an alternate electron acceptor. TorS is the membrane associated sensor kinase which detects the presence of trimethylamine N-oxide (TMAO) in the medium and phosphorylates its cognate response regulator, TorR. Thus activated, phosphorylated TorR binds to a region upstream of TorC and induces the torCAD operon. TorR has also been shown to regulate the expression of genes involved in the response to extreme pH leading to the suggestion that the TorSR system also triggers alkaline stress defence mechanisms to counteract the increasing pH resulting from TMA production.

The periplasmic TorT protein acts upstream of the TorSR two-component system. TorT binds to TMAO and interacts with the periplasmic domain of TorS thus suggesting that the TorS activating signal may be a TMAO-TorT complex.

Created 16-Aug-2010 by Mackie A, Macquarie University


Jourlin96: Jourlin C, Bengrine A, Chippaux M, Mejean V (1996). "An unorthodox sensor protein (TorS) mediates the induction of the tor structural genes in response to trimethylamine N-oxide in Escherichia coli." Mol Microbiol 1996;20(6);1297-306. PMID: 8809780

Yamamoto05: Yamamoto K, Hirao K, Oshima T, Aiba H, Utsumi R, Ishihama A (2005). "Functional characterization in vitro of all two-component signal transduction systems from Escherichia coli." J Biol Chem 280(2);1448-56. PMID: 15522865

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Ansaldi00: Ansaldi M, Simon G, Lepelletier M, Mejean V (2000). "The TorR high-affinity binding site plays a key role in both torR autoregulation and torCAD operon expression in Escherichia coli." J Bacteriol 2000;182(4);961-6. PMID: 10648521

Ansaldi01: Ansaldi M, Jourlin-Castelli C, Lepelletier M, Theraulaz L, Mejean V (2001). "Rapid dephosphorylation of the TorR response regulator by the TorS unorthodox sensor in Escherichia coli." J Bacteriol 2001;183(8);2691-5. PMID: 11274133

Bordi03: Bordi C, Theraulaz L, Mejean V, Jourlin-Castelli C (2003). "Anticipating an alkaline stress through the Tor phosphorelay system in Escherichia coli." Mol Microbiol 48(1);211-23. PMID: 12657056

GarciaHorsman94: Garcia-Horsman JA, Barquera B, Rumbley J, Ma J, Gennis RB (1994). "The superfamily of heme-copper respiratory oxidases." J Bacteriol 176(18);5587-600. PMID: 8083153

Hirakawa03: Hirakawa H, Nishino K, Hirata T, Yamaguchi A (2003). "Comprehensive studies of drug resistance mediated by overexpression of response regulators of two-component signal transduction systems in Escherichia coli." J Bacteriol 185(6);1851-6. PMID: 12618449

Jourlin96a: Jourlin C, Simon G, Pommier J, Chippaux M, Mejean V (1996). "The periplasmic TorT protein is required for trimethylamine N-oxide reductase gene induction in Escherichia coli." J Bacteriol 1996;178(4);1219-23. PMID: 8576063

Jourlin97: Jourlin C, Ansaldi M, Mejean V (1997). "Transphosphorylation of the TorR response regulator requires the three phosphorylation sites of the TorS unorthodox sensor in Escherichia coli." J Mol Biol 1997;267(4);770-7. PMID: 9135110

Pao95: Pao GM, Saier MH (1995). "Response regulators of bacterial signal transduction systems: selective domain shuffling during evolution." J Mol Evol 1995;40(2);136-54. PMID: 7699720

Parkinson92: Parkinson JS, Kofoid EC (1992). "Communication modules in bacterial signaling proteins." Annu Rev Genet 1992;26;71-112. PMID: 1482126

Parkinson93: Parkinson JS (1993). "Signal transduction schemes of bacteria." Cell 1993;73(5);857-71. PMID: 8098993

Pascal91: Pascal MC, Lepelletier M, Giordano G, Chippaux M (1991). "A regulatory mutant of the trimethylamine N-oxide reductase of Escherichia coli K12." FEMS Microbiol Lett 62(2-3);297-300. PMID: 2040436

Simon94: Simon G, Mejean V, Jourlin C, Chippaux M, Pascal MC (1994). "The torR gene of Escherichia coli encodes a response regulator protein involved in the expression of the trimethylamine N-oxide reductase genes." J Bacteriol 1994;176(18);5601-6. PMID: 8083154

Simon95: Simon G, Jourlin C, Ansaldi M, Pascal MC, Chippaux M, Mejean V (1995). "Binding of the TorR regulator to cis-acting direct repeats activates tor operon expression." Mol Microbiol 1995;17(5);971-80. PMID: 8596446

Stock89: Stock JB, Ninfa AJ, Stock AM (1989). "Protein phosphorylation and regulation of adaptive responses in bacteria." Microbiol Rev 53(4);450-90. PMID: 2556636

Stock90: Stock JB, Stock AM, Mottonen JM (1990). "Signal transduction in bacteria." Nature 1990;344(6265);395-400. PMID: 2157156

ToroRoman05: Toro-Roman A, Wu T, Stock AM (2005). "A common dimerization interface in bacterial response regulators KdpE and TorR." Protein Sci 14(12);3077-88. PMID: 16322582

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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