Assembly of transcriptionally active RNA polymerase I initiation factor SL1 from recombinant subunits.
Initiation of ribosomal RNA synthesis by RNA polymerase I requires the promoter selectivity factor SL1, which consists of the TATA-binding protein, TBP, and three associated factors, TAFIS 110, 63, and 48. Here the in vivo and in vitro assembly of functional SL1 complexes from recombinant TAFIS and TBP are reported. Complexes containing TBP and all three TAFIS were as active in supporting transcription from the human ribosomal RNA gene promoter as endogenous SL1, whereas partial complexes without TBP did not efficiently direct transcription in vitro. These results suggest that TAFIS 110, 63, and 48, together with TBP, are necessary and sufficient to reconstitute a transcriptionally active SL1 complex.
Zomerdijk
J C
JC
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204.
Beckmann
H
H
Comai
L
L
Tjian
R
R
D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D035463:Pol1 Transcription Initiation Complex Proteins; D011401:Promoter Regions, Genetic; D012335:RNA, Ribosomal / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016385:TATA Box; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D012335:RNA, Ribosomal; D011993:Recombinant Fusion Proteins; C091131:TAF1A protein, human; C091129:TAF1B protein, human; C486319:TAF1C protein, human; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors; C063844:transcription factor UBF; C063660:transcription initiation factor TIF-IB