Analysis of the stimulatory factor of RNA polymerase II in the initiation and elongation complex

The interaction between RNA polymerase II and its specific stimulatory factor S-II was studied using each component purified to near homogeneity. It was found that RNA polymerase II and S-II form a complex in the absence of DNA and nucleoside triphosphates, although their interaction was weak. This interaction became stable in the presence of a template and substrates, and a stoichiometric amount of S-II was found to remain in the transcription machinery during RNA chain elongation.