THE TATA BOX-BINDING PROTEIN-1 (TBP-1) OF MAIZE DISPLAYS PROMOTER-SPECIFIC DNA-BINDING AFFINITIES

Recombinant TATA box binding protein (TBP) of maize was analysed by DN A footprinting and electrophoretic mobility shift experiments to asses s its affinity to TATA box containing Po/II promoter fragments of seve ral plant genes and a Po/I gene promoter. While the proximal zein prom oter P2 and the viral 35S promoter easily form in vitro complexes with TBP, the distal zein promoter P1, the Shrunken promoter and a maize r RNA gene promoter required the assistance of a yeast protein fraction with TFIIA activity. This latter capability demonstrates the potential of yeast general transcription factors as tools for studies on the fo rmation of plant transcriptional complexes.