Figure 4.

The denaturation bubble removes a barrier to transcription from spoIIG. Reactions containing 4 nM template DNA (▵, wild-type; ○, MB8NT; or •, MB12NT), 80 mM potassium acetate, 40 nM RNA polymerase and the initiating nucleotides ATP and [α-³²P]GTP in transcription buffer were incubated at the indicated temperatures. After 2 min complexes were challenged with a mixture of UTP, CTP, and heparin. Products of the reactions were separated on a polyacrylamide gel as described in the Materials and Methods. The amount of transcript produced was quantitated by using a Molecular Dynamics PhosphorImager SI and imagequant 1.0 software and normalized to that produced from the MB12NT template at 37°C (100%).