2000. Assembly of partial TFIID complexes in mammalian cells reveals distinct activities associated with individual TATA box-binding protein-associated factors

The TATA box-binding protein (TBP) and TBP-associ-ated factors (TAFIIs) compose the general transcription factor TFIID. The TAFII subunits mediate activated transcription by RNA polymerase II by interacting di-rectly with site-specific transcriptional regulators. TAFIIs also participate in promoter recognition by con-tacting core promoter elements in the context of TFIID. To further dissect the contribution of individual TAFII subunits to mammalian TFIID function, we employed a vaccinia virus-based protein expression system to study protein-protein interactions and complex assembly. We identified the domains of human (h) TAFII130 required for TAFII-TAFII interactions and formation of a complex with hTBP, hTAFII100, and hTAFII250. Functional anal-ysis of partial TFIID complexes formed in vivo indicate