Open AccessAn enhancer-like element present in the promoter of a T-DNA gene from the Ti plasmid of Agrobacterium tumefaciens
Author(s) -
William A. Bruce,
R Bandyopadhyay,
William B. Gurley
Publication year - 1988
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.85.12.4310
Subject(s) - enhancer , microbiology and biotechnology , agrobacterium tumefaciens , biology , promoter , transcription (linguistics) , gene , upstream activating sequence , ti plasmid , tata box , activator (genetics) , response element , genetics , gene expression , transformation (genetics) , linguistics , philosophy
The promoter of the780 gene of T-right [Thomashow, M., Nutter, R., Montoya, A., Gordon, M. & Nester, E. (1980)Cell 19, 729-739] fromAgrobacterium tumefaciens Ti plasmid (pTi15955) was shown to contain an upstream cis-acting element (activator) having enhancer-like properties. To characterize the properties of this promoter element, it was placed in both polarities, upstream and downstream of a Δ-37 deletion mutant of the780 gene. The Δ-37 deletion contains the entire780 gene with the 5′ flanking sequences deleted upstream of TATA to -37. The effect of the activator onin vivo transcriptional activity was assessed by S1 nuclease mapping utilizing a homologous reference gene as an internal standard. Transcript levels from sunflower crown gall tumors were between 127% and 90% of the wild-type780 gene depending on the polarity of the activator element when placed directly upstream to the780 gene Δ-37 promoter. Repositioning the activator element 613 base pairs further upstream increased transcription by 2-fold regardless of polarity. However, the activator element did not promote transcription when placed in either polarity ≈200 base pairs downstream of the poly(A) addition site. Upstream promoter fragments (TATA-distal) from the octopine synthase (ocs ) and agropine synthase (ags ) genes were also tested for activation of the Δ-37 construction. Theocs sequences activated transcription of the Δ-37 deletion to 14% of wild-type levels when placed upstream in the B (reverse) orientation. All other constructions with theocs andags sequences showed no enhancement of promoter activity.