Transcription of the Bacillus subtilis bacteriophage phi 3T in vitro

The in vitro transcription pattern of Bg/II-digested phi 3T DNA is described. Eight Bg/II fragments that hybridized to in vitro transcription products were unequivocally identified. A further hybridizing region corresponding to a Bg/II triplet was also revealed, giving a total of nine to 11 Bg/II fragments. These represent 47 to 53% of the phi 3T genome. Transcription was shown to initiate within Bg/II fragments B, G, C, H, I, F and J, implying that all of these contain at least one promoter. The relevance of these data to the construction of a cloning vector based on phi 3T is discussed.