Nucleotide sequence and transcription of a bacteriophage 29 early promoter

We have studied the in vitro and in vivo transcription of a promoter for Bacillus subtilis RNA polymerase on bacteriophage phi 29 DNA. The promoter is identified as an early promoter as it is transcribed in vitro by uninfected B. subtilis sigma 55-containing RNA polymerase; is transcribed in vivo at both 7 min after infection and in the presence of chloramphenicol; and is transcribed right to left on the standard phi 29 map. The nucleotide sequence of the promoter and the initiation site for RNA synthesis are reported. We have also examined the kinetics of RNA synthesis initiation using a single round run-off transcription assay. The overall rate of initiation was found to be 1.6 X 10(6) M-1 s-1 while the rate of conversion of unstable to stable polymerase-promoter complexes was 0.049 s-1. These values are comparable to those for similar promoters for Escherichia coli RNA polymerase.