Although the mechanisms of transcriptional regulation by RNA polymerase II are apparently highly conserved from yeast to man, the identification of a yeast TATA-binding protein (TBP)-TBP-associated factor (TAF(II)) complex comparable to the metazoan TFIID component of the basal transcriptional machinery has remained elusive. Here, we report the isolation of a yeast TBP- TAF(II) complex which can mediate transcriptional activation by GAL4-VP16 in a highly purified yeast in vitro transcription system. We have cloned and sequenced the genes encoding four of the multiple yeast TAFn proteins comprising the TBP-TAF(II) multisubunit complex and find that they are similar at the amino acid level to both human and Drosophila TFIID subunits. Using epitope-tagging and immunoprecipitation experiments, we demonstrate that these genes encode bona fide TAF proteins and show that the yeast TBP- TAF(II) complex is minimally composed of TBP and seven distinct yTAF(II) proteins ranging in size from M(r) = 150,000 to M(r) = 25,000. In addition, by constructing null alleles of the cloned TAF-encoding genes, we show that normal function of the TAF-encoding genes is essential for yeast cell viability.
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Publication status||Published - 1995 Aug 29|
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