The complete nucleotide sequence of the TL-DNA of the Agrobacterium tumefaciens plasmid pTiAch5.

Abstract
We have determined the complete primary structure (13 637 bp) of the TL‐region of Agrobacterium tumefaciens octopine plasmid pTiAch5 . This sequence comprises two small direct repeats which flank the TL‐region at each extremity and are involved in the transfer and/or integration of this DNA segment in plants. TL‐DNA specifies eight open‐reading frames corresponding to experimentally identified transcripts in crown gall tumor tissue. The eight coding regions are not interrupted by intervening sequences and are separated from each other by AT‐rich regions. Potential transcriptional control signals upstream of the 5′ and 3′ ends of all the transcribed regions resemble typical eukaryotic signals: (i) transcriptional initiation signals (‘TATA’ or Goldberg‐ Hogness box) are present upstream to the presumed translational start codons; (ii) ‘ CCAAT ‘ sequences are present upstream of the proposed ‘TATA’ box; (iii) polyadenylation signals are present in the 3′‐untranslated regions. Furthermore, no Shine‐Dalgarno sequences are present upstream of the presumed translational start codons.