Nucleotide sequence and transcript mapping of the tmr gene of the pTiA6NC octopine Ti-plasmid: a bacterial gene involved in plant tumorigenesis.

The nucleotide sequence of a tumor morphology gene, tmr, from the Agrobacterium tumefaciens Ti-plasmid, pTiA6NC, and its flanking 5' region was determined by M13 "dideoxy" procedures. The DNA sequence reveals an open reading frame capable of encoding a 240 amino acid protein. We have identified the polyadenylated transcript initiation and termination sits by S1 nuclease mapping. The extent of the sequence required for transcription 5' to the start of transcription has been delimited by two transposon insertions. The first of these maps at -- 121 with respect to transcription initiation and results in the wild-type phenotype, the second insertion maps at about -85 and results in a tmr phenotype.