CLONING AND EXPRESSION OF DROSOPHILA TAF(II)60 AND HUMAN TAF(II)70 REVEAL CONSERVED INTERACTIONS WITH OTHER SUBUNITS OF TFIID

Regulation of transcription initiation by RNA polymerase II requires TFIID, a multisubunit complex composed of the TATA binding protein (TBP) and at least seven tightly associated factors (TAFs). Some TAFs act as direct targets or coactivators for promoter-specific activators while others serve as interfaces for TAF - TAF interactions. Here, we report the molecular cloning, expression and characterization of Drosophila dTAF(II)60 and its human homolog, hTAF(II)70. Recombinant TAF(II)60/70 binds weakly to TBP and tightly to the largest subunit of TFIID, TAF(II)250. In the presence of TAF(II)60/70, TBP and TAF(II)250, a stable ternary complex is formed. Both the human and Drosophila proteins directly interact with another TFIID subunit, dTAF(II)40. Our findings reveal that Drosophila TAF(II)60 and human TAF(II)70 share a high degree of structural similarity and that their interactions with other subunits of TFIID are conserved.