Figure 1.

Spo0ABD induces DNA strand separation at the spoIIG promoter. Transcription reactions containing 4 nM template DNA, labeled at the BamHI site with [γ-³²P]ATP, 400 nM Spo0ABD, or 40 nM RNA polymerase (RNAP) or both in combination with different initiating nucleotides (as indicated above each lane) were treated with KMnO₄. Modified DNA was cleaved with piperidine, the cleavage products were analyzed on an 8% polyacrylamide gel containing 7 M urea and the gel was exposed to x-ray film. A representation of the spoIIG promoter in pUCIIGtrpA is shown on the left. Positions of restriction endonuclease sites and primers used in mutagenesis are indicated. The HindIII and BamHI sites are not located to scale. Positions of 0A boxes (▧) and −10 and −35 sequences (□) are shown. Thymines sensitive to KMnO4 modification are indicated by dots to the right (sensitive in the absence of ATP plus GTP) and dots to the left (additional sites sensitive in the presence of ATP and GTP). Nucleotide positions are labeled relative to the start site of transcription (+1).