THE DNA-BINDING SUBUNIT OF HUMAN TRANSCRIPTION FACTOR-IID CAN INTERACT WITH THE TATA BOX AS A MULTIMER

Transcription initiation from eukaryotic protein-coding genes is a com plex process that minimally requires RNA polymerase (pol) II (B) and a t least seven general transcription factors. The 38-kDa subunit (TBP) of the human general transcription factor TFIID recognizes the TATA se quence element and initiates the assembly of the other general transcr iption factors and RNA pol II. It is believed, based on experiments wi th yeast recombinant protein, that TBP binds as a monomer to DNA. Usin g purified recombinant human TBP protein we find that TBP interacts wi th the TATA element as both a monomer and a dimer. The multimeric bind ing of TBP to DNA revealed by this study has important implications fo r the role of TBP in transcription initiation and suggests novel mecha nisms whereby other transcription factors may interact with a RNA pol II preinitiation complex.