ARABIDOPSIS-THALIANA CONTAINS 2 GENES FOR TFIID

THE general transcription initiation factor TFIID plays a primary part in the activation of eukaryotic genes transcribed by RNA polymerase II. Binding of TFIID to the TATA box initiates the assembly of other general transcription factors as well as RNA polymerase II at the promoter resulting in a preinitiation complex capable of accurate transcription initiation in vitro1-3. Human TFIID has been shown to interact with various regulatory factors4-8. The observation that stimulation of transcription by different trans-acting factors is mediated through distinct TATA elements led to the suggestion that different types of TFIID may exist in yeast9-11, humans12-15 and plants16. Here we report the cloning and characterization of two distinct TFIID complementary DNA clones from Arabidopsis thaliana. Furthermore, we have found that TFIID from Arabidopsis and other organisms shows homology to helix-loop-helix proteins. © 1990 Nature Publishing Group.