Study of the TmoS TmoT two component system Towards the functional characterisation of the family of TodS TodT like systems       
Yazarlar (6)
Silva-Jimenez Hortencia
Garcia-Fontana Cristina
Prof. Dr. Bilge Hilal ÇADIRCI Tokat Gaziosmanpaşa Üniversitesi, Türkiye
Ramos-Gonzalez Maria Isabel
Juan Luis Ramos
Krell Tino
Makale Türü Açık Erişim Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale
Dergi Adı MICROBIAL BIOTECHNOLOGY
Dergi ISSN 1751-7907
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q4
Makale Dili İngilizce
Basım Tarihi 07-2012
Cilt No 5
Sayı 4
Sayfalar 489 / 500
DOI Numarası 10.1111/j.1751-7915.2011.00322.x
Makale Linki http://www.ncbi.nlm.nih.gov/pubmed/22212183
Özet
The two-component system TmoS/TmoT controls the expression of the toluene-4-monooxygenase pathway in Pseudomonas mendocina RK1 via modulation of PtmoX activity. The TmoS/TmoT system belongs to the family of TodS/TodT like proteins. The sensor kinase TmoS is a 108kDa protein composed of seven different domains. Using isothermal titration calorimetry we show that purified TmoS binds a wide range of aromatic compounds with high affinities. Tightest ligand binding was observed for toluene (KD=150nM), which corresponds to the highest affinity measured between an effector and a sensor kinase. Other compounds with affinities in the nanomolar range include benzene, the 3 xylene isomers, styrene, nitrobenzene or p-chlorotoluene. We demonstrate that only part of the ligands that bind to TmoS increase protein autophosphorylation in vitro and consequently pathway expression in vivo. These compounds are referred to as agonists. Other TmoS ligands, termed antagonists, failed to increase TmoS autophosphorylation, which resulted in their incapacity to stimulate gene expression in vivo. We also show that TmoS saturated with different agonists differs in their autokinase activities. The effector screening of gene expression showed that promoter activity of PtmoX and PtodX (controlled by the TodS/TodT system) is mediated by the same set of 22 compounds. The common structural feature of these compounds is the presence of a single aromatic ring. Among these ligands, toluene was the most potent inducer of both promoter activities. Information on the TmoS/TmoT and TodS/TodT system combined with a sequence analysis of family members permits to identify distinct features that define this protein family. © 2011 The Authors. Microbial Biotechnology © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
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