Reconstitution of yeast RNA polymerase I transcription in vitro from purified components. TATA-binding protein is not required for basal transcription.
Five purified protein components, RNA polymerase I, Rrn3p, core factor, TBP (TATA-binding protein), and upstream activation factor, are sufficient for high level transcription in vitro from the Saccharomyces cerevisiae rDNA promoter. Rrn3p and pol I form a complex in solution that is active in specific initiation. Three protein components, pol I, Rrn3p, and core factor, and promoter sequence to -38, suffice for basal transcription. Unlike pol II and pol III, yeast pol I basal transcription does not require TBP. Instead, TBP, upstream activation factor, and the upstream element of the promoter together stimulate pol I basal transcription to a fully activated level. The role of TBP in pol I transcription is fundamentally different from its role in pol II or pol III transcription.
Pubmed ID: 9837969 RIS Download
Amino Acid Sequence | DNA, Ribosomal | DNA-Binding Proteins | Fungal Proteins | Molecular Sequence Data | Pol1 Transcription Initiation Complex Proteins | Promoter Regions, Genetic | RNA Polymerase I | Saccharomyces cerevisiae | Saccharomyces cerevisiae Proteins | TATA Box | TATA-Box Binding Protein | Transcription Factors | Transcription, Genetic