MONOCLONAL-ANTIBODIES DIRECTED AGAINST THE AMINO-TERMINAL DOMAIN OF HUMAN TBP CROSS-REACT WITH TBP FROM OTHER SPECIES

The TATA box-binding protein (TBP) is a key transcription factor requi red for transcription by all three eukaryotic RNA polymerases, It cons ists of a conserved carboxy-terminal DNA binding domain and a highly d ivergent amino terminal domain. TBP and different sets of TBP-associat ed factors (TAFs) constitute at least four multisubunit complexes refe rred to as SL1, TFIID, TFIIIB, and SNAP(C). SL1, TFIID, and TFIIIB are required for transcription by RNA polymerases I, II, and III, respect ively, while the SNAP complex is involved in transcription of the smal l nuclear RNA (snRNA) genes by RNA polymerases II and III, TBP also as sociates with a number of basal transcription factors such as TFIIA an d TFIIB, and with several regulatory factors such as VP16, E1A, and p5 3, Here we describe the characterization of a panel of monoclonal anti bodies (MAbs) directed against the amino-terminal domain of human TBP, These MAbs recognize different TBP epitopes, some of which have been precisely defined, Different MAbs recognize different TBP-containing c omplexes and several of them crossreact with TBP from other species, T hese antibodies can be used to purify TBP-containing complexes in a fu nctional form and should be useful to identify new protein-protein int eractions involving TBP.