PRIMARY STRUCTURE OF PTIBO542 T-DNA

The primary structure of T(L)-DNA of the pTiBo542 plasmid of the super virulent strain A281 of Agrobacterium tumefaciens was studied. Genes 1 and 6b were assigned to BamHI, SalI, and XbaI sites by using the labe led probes complementary to plasmid pTiAch5 fragments. BamHI fragments encompassing almost all of the T(L)-DNA except a 450-bp-long fragment were cloned in pTZ19R. The 5' part of the 6b gene and the upstream no ntranscribed region were sequenced. Southern hybridization data and th e comparison of nucleotide sequences revealed high homology between th e corresponding regions of T(L)-DNA of the pTiBo542 and pTiAch5 plasmi ds.