Cross-regulation between a novel two-component signal transduction system for catabolism of toluene in Pseudomonas mendocina and the TodST system from Pseudomonas putida.
The tmoABCDEF genes encode the toluene-4-monooxygenase from Pseudomonas mendocina KR1. Upstream from the tmoA gene an open reading frame, tmoX, encoding a protein 83% identical to TodX (todX being the initial gene in the todXFC1C2BADEGIH operon from Pseudomonas putida DOT-T1E) was found. The tmoX gene is also the initial gene in the tmoXABCDEF gene cluster. The transcription initiation point from the tmoX promoter was mapped, and the sequence upstream revealed striking identity with the promoter of the tod operon of P. putida. The tod operon is regulated by a two-component signal transduction system encoded by the todST genes. Two novel genes from P. mendocina KR1, tmoST, were rescued by complementation of a P. putida DOT-T1E todST knockout mutant, whose gene products shared about 85% identity with TodS-TodT. We show that transcription from P(tmoX) and P(todX) can be mediated by TmoS-TmoT or TodS-TodT, in the presence of toluene, revealing cross-regulation between these two catabolic pathways.
Ramos-González
María-Isabel
MI
Department of Biochemistry and Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain. maribel.ramos@eez.csic.es
Olson
Monica
M
Gatenby
Anthony A
AA
Mosqueda
Gilberto
G
Manzanera
Maximino
M
Campos
María J
MJ
Víchez
Susana
S
Ramos
Juan L
JL
D001426:Bacterial Proteins; D005810:Multigene Family; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000502:physiology*; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism*; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014050:Toluene / Q000378:metabolism*; D015534:Trans-Activators / Q000502:physiology*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; C104650:TodT protein, Pseudomonas putida; D015534:Trans-Activators; D014050:Toluene; D011494:Protein Kinases; C104649:TodS protein, Pseudomonas putida