Effects of activation-defective TBP mutations on transcription initiation in yeast

TBP mutations disrupt TFIIB recruitment to early preinitiation complexes and affect interactions of GAL4-VP16 with VP16, TFIIB or an unidentified component. Mutations in yeast TBP selectively block activator GAL4-VP16-dependent are identified. GAL4-VP16 mechanism involves both direct interactions with TBP and a corresponding induction of an activation-specific TBP-TFIIB-promoter complex.