These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Regulation of tfdCDEF by tfdR of the 2,4-dichlorophenoxyacetic acid degradation plasmid pJP4.
    Author: Kaphammer B, Kukor JJ, Olsen RH.
    Journal: J Bacteriol; 1990 May; 172(5):2280-6. PubMed ID: 2158967.
    Abstract:
    The closely linked structural genes tfdCDEF borne on the 2,4-dichlorophenoxyacetic acid (TFD) catabolic plasmid, pRO101, were cloned into vector pRO2321 as a 12.6-kilobase-pair BamHI C fragment and designated pRO2334. The first gene in this cluster, tfdC, encodes chlorocatechol 1,2-dioxygenase and was expressed constitutively. Chlorocatechol 1,2-dioxygenase expression by pRO2334 was repressed in trans by the negative regulatory element, tfdR, on plasmid pRO1949. Derepression of tfdC was achieved when Pseudomonas aeruginosa PAO4032 containing both plasmids pRO2334 and pRO1949 was grown in minimal glucose medium containing TFD, 2,4-dichlorophenol, or 4-chlorocatechol, suggesting that TFD and other pathway intermediates can act as inducing compounds. Genetic organization of the tfdCDEF cluster was established by deletion of the tfdC gene, which resulted in the loss of tfdD and tfdE activity, suggesting that genes tfdCDEF are organized in an operon transcribed from the negatively regulated promoter of tfdC. Deletion subcloning of pRO1949 was used to localize tfdR to a 1.2-kilobase-pair BamHI-XhoI region of the BamHI E fragment of plasmid pRO101. The tfdR gene product was shown not to regulate the expression of tfdB, which encodes 2,4-dichlorophenol hydroxylase.
    [Abstract] [Full Text] [Related] [New Search]