TouR-mediated effector-independent growth phase-dependent activation of the sigma54 Ptou promoter of Pseudomonas stutzeri OX1.

@article{citeulike:3038834, abstract = {Transcription of the catabolic touABCDEF operon, encoding the toluene-o-xylene monooxygenase of Pseudomonas stutzeri OX1, is driven by the sigma(54)-dependent Ptou promoter, whose activity is controlled by the phenol-responsive NtrC-like activator TouR. In this paper we describe for the first time a peculiar characteristic of this system, namely, that Ptou transcription is activated in a growth phase-dependent manner in the absence of genuine effectors of the cognate TouR regulator. This phenomenon, which we named gratuitous activation, was observed in the native strain P. stutzeri OX1, as well as in a Pseudomonas putida PaW340 host harboring the reconstructed tou regulatory circuit. Regulator-promoter swapping experiments demonstrated that the presence of TouR is necessary and sufficient for imposing gratuitous activation on the Ptou promoter, as well as on other sigma(54)-dependent catabolic promoters, whereas the highly similar phenol-responsive activator DmpR is unable to activate the Ptou promoter in the absence of effectors. We show that this phenomenon is specifically triggered by carbon source exhaustion but not by nitrogen starvation. An updated model of the tou regulatory circuit is presented.}, address = {Dipartimento di Biologia Strutturale e Funzionale, Universit\`{a} degli Studi di Milano, Milan, Italy.}, author = {Solera, D. and Arenghi, F. L. and Woelk, T. and Galli, E. and Barbieri, P. }, citeulike-article-id = {3038834}, doi = {http://dx.doi.org/10.1128/JB.186.21.7353-7363.2004}, issn = {0021-9193}, journal = {Journal of bacteriology}, keywords = {biodegradation, for-the-review, ntrc, regulation, sigma54, tour, transcription}, month = {November}, number = {21}, pages = {7353--7363}, posted-at = {2008-07-24 10:47:13}, priority = {3}, title = {TouR-mediated effector-independent growth phase-dependent activation of the sigma54 Ptou promoter of Pseudomonas stutzeri OX1.}, url = {http://dx.doi.org/10.1128/JB.186.21.7353-7363.2004}, volume = {186}, year = {2004} }

TY - JOUR ID - citeulike:3038834 L3 - citeulike-article-id:3038834 TI - TouR-mediated effector-independent growth phase-dependent activation of the sigma54 Ptou promoter of Pseudomonas stutzeri OX1. JF - Journal of bacteriology VL - 186 IS - 21 SP - 7353 EP - 7363 AD - Dipartimento di Biologia Strutturale e Funzionale, Università degli Studi di Milano, Milan, Italy. SN - 0021-9193 N2 - Transcription of the catabolic touABCDEF operon, encoding the toluene-o-xylene monooxygenase of Pseudomonas stutzeri OX1, is driven by the sigma(54)-dependent Ptou promoter, whose activity is controlled by the phenol-responsive NtrC-like activator TouR. In this paper we describe for the first time a peculiar characteristic of this system, namely, that Ptou transcription is activated in a growth phase-dependent manner in the absence of genuine effectors of the cognate TouR regulator. This phenomenon, which we named gratuitous activation, was observed in the native strain P. stutzeri OX1, as well as in a Pseudomonas putida PaW340 host harboring the reconstructed tou regulatory circuit. Regulator-promoter swapping experiments demonstrated that the presence of TouR is necessary and sufficient for imposing gratuitous activation on the Ptou promoter, as well as on other sigma(54)-dependent catabolic promoters, whereas the highly similar phenol-responsive activator DmpR is unable to activate the Ptou promoter in the absence of effectors. We show that this phenomenon is specifically triggered by carbon source exhaustion but not by nitrogen starvation. An updated model of the tou regulatory circuit is presented. KW - biodegradation KW - for-the-review KW - ntrc KW - regulation KW - sigma54 KW - tour KW - transcription AU - Solera, D AU - Arenghi, FL AU - Woelk, T AU - Galli, E AU - Barbieri, P PY - 2004/11// UR - http://dx.doi.org/10.1128/JB.186.21.7353-7363.2004 ER -