Study of the TmoS/TmoT two-component system: towards the functional characterization of the family of TodS/TodT like systems.
Bottom Line: Tightest ligand binding was observed for toluene (K(D) = 150 nM), which corresponds to the highest affinity measured between an effector and a sensor kinase.Other TmoS ligands, termed antagonists, failed to increase TmoS autophosphorylation, which resulted in their incapacity to stimulate gene expression in vivo.Among these ligands, toluene was the most potent inducer of both promoter activities.
Affiliation: Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/ Prof. Albareda 1, Granada, Spain. .Show MeSH
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Mentions: The alignment of the promoters PtodX and PtmoX (Fig. S3) show 68% of sequence identity. The binding of TodT to PtodX has been studied extensively for P. putida strains F1 (Lau et al., 1997) and DOT‐T1E (Lacal et al., 2006; 2008a,b). In total five monomers were found to bind to boxes 1–3, of which boxes 1 and 2 are pseudopalindromes whereas box 3 corresponds to a half‐palindrome. In the alignment of promoters PtodX and PtmoX both these binding sites are well conserved and are thus proposed to form TmoT operator sites. In addition, the StyR operator has been experimentally identified for the protein from P. fluorescens[Leoni and colleagues (2005) and Rampioni and colleagues (2008)] and operator sites were predicted for the for Pseudomonas sp. strain Y2 (Velasco et al., 1998). The alignment of either experimentally determined or predicted operator sites of family members is shown in Fig. 2. From this alignment the following consensus can be derived: AAA‐x2‐[AT]‐x2‐GT‐[TA]‐[TC].
Affiliation: Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/ Prof. Albareda 1, Granada, Spain. .