Similarities between nucleotide sequences of insertion elements of Agrobacterium tumefaciens and Pseudomonas savastanoi in relation to Agrobacterium tumefaciens T sub(C)-DNA

The authors compared the nucleotide sequences of IS426 of Agrobacterium tumefaciens and IS51 Pseudomonas savastanoi . Significant homology was observed between the inverted repeats of both IS elements. In addition, a strong nucleotide sequence homology was found between a 105-bp region of IS426, including the right inverted repeat, and a portion of the T sub(C)-DNA of pTil5955 from A. tumefaciens). It can be seen that part of the T sub(C)-DNA resembles a prokaryotic transposable element. It terminates in inverted repeats, since the inverted repeats of IS51 and IS426 show striking homology, and it is flanked by a 4 bp sequence (TGTT) duplication. It can therefore be speculated that transposition might have played a role in the origin of T sub(C)-DNA.