Detection of a potential transcription control sequence on the cauliflower mosaic virus genome by dinucleotide primed "in vitro" transcription.

The three sites of selective dinucleotide-primed "in vitro" transcription initiation on a cloned cauliflower mosaic virus DNA fragment have been localised by S1 nuclease mapping. Two of these sites lie within a region which has been shown to be essential for transcription complex formation on the viral sequences, one corresponding to a nuclease S1 hypersensitive site and the other to an imperfect repeat 100bp downstream. These sequences show striking homology with known transcription control sequences. These observations and the effect of the sequences on "in vitro" transcription raise the possibility that they may be involved in control of transcription of the viral genome.