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Overdrive , a T‐DNA transmission enhancer on the A. tumefaciens tumour‐inducing plasmid
Author(s) -
Peralta Ernest G.,
Hellmiss Renate,
Ream Walt
Publication year - 1986
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1986.tb04338.x
Subject(s) - biology , plasmid , enhancer , agrobacterium tumefaciens , dna , transmission (telecommunications) , microbiology and biotechnology , genetics , gene , transformation (genetics) , gene expression , electrical engineering , engineering
During crown gall tumorigenesis a specific segment of the Agrobacterium tumefaciens tumour‐inducing (Ti) plasmid, the T‐DNA, integrates into plant nuclear DNA. Similar 23‐bp direct repeats at each end of the T region signal T‐DNA borders, and T‐DNA transmission (transfer and integration) requires the right‐hand direct repeat. A chemically synthesized right border repeat in its wild‐type orientation promotes T‐DNA transmission at a low frequency; Ti plasmid sequences which normally flank the right repeat greatly stimulate the process. To identify flanking sequences required for full right border activity, we tested the activity of a border repeat surrounded by different amounts of normal flanking sequences. Efficient T‐DNA transmission required a conserved sequence (5′ TAAPuTPy‐CTGTPuT‐TGTTTGTTTG 3′) which lies to the right of the two known right border repeats. In either orientation, a synthetic oligonucleotide containing this conserved sequence greatly stimulated the activity of a right border repeat, and a deletion removing 15 bp from the right end of this sequence destroyed its stimulatory effect. Thus, wild‐type T‐DNA transmission required both the 23‐bp right border repeat and a conserved flanking sequence which we call overdrive .