RNA-POLYMERASE-I FROM SACCHAROMYCES-CEREVISIAE DEPENDS ON AN ADDITIONAL FACTOR TO RELEASE TERMINATED TRANSCRIPTS FROM THE TEMPLATE

Terminated transcripts were generated at the ends of linearized DNA te mplates and at DNA-bound lac repressor by in vitro transcription with highly enriched or purified yeast RNA polymerase I (pol I), The releas e of the synthesized transcripts from the DNA was analyzed using immob ilized DNA as template for the transcription reaction. An additional a ctivity distinguishable from pol I was necessary to remove the termina ted RNA from the template, Efficiency of transcript release could be i mproved if a thymidine-rich DNA fragment was located upstream of the t ranscriptional arrest caused by the DNA-bound lac repressor, The relea se activity interacted with different forms of polymerases, poll able to initiate on the ribosomal gene promoter and pol I only active in no n-specific transcription. (C) 1997 Federation of European Biochemical Societies.