Sequence analysis of the vir-region from Agrobacterium tumefaciens octopine Ti plasmid pTi15955.

corrected for the insertion of the nucleotide ‘G’ between base The nucleotide sequence of 42 775 bp of the vir-region from 3275 and 3276 giving two G residues instead of one). For the Agrobacterium tumefaciens octopine Ti plasmid pTi15955 the first time, the sequences of the remaining vir operons is reported here. Although the nucleotide sequences of several including the virC, virD and virE operons of pTi15955, as parts of this region from this or closely related plasmids have well as the regions between the vir operons, are reported here. been published previously, the present work establishes for Several complete or partial insertion (IS ) elements were the first time the complete arrangement of all the essential found in the intergenic areas between certain vir operons. virulence genes and their intergenic regions of an octopine Ti An insert of 250 bp was found between the virK and virA plasmid. The disruption of some of the intergenic areas by operons which showed 85% identity to an internal region of insertion (IS) elements is typical for the octopine Ti plasmids. IS66, an IS element found previously in the T L -region of the Several new ORFs were identified, including ORFs immediately octopine Ti plasmid of mutant A66 (Machida et al., 1984). downstream of virD4 and virE2, which probably represent new This insert was named IS66-p. At 484 bp downstream of the genes involved in virulence. virJ stop codon an insert of 834 bp with 15 bp imperfect terminal inverted repeats (IRs) was identified, which is