TBP recruitment to the U1 snRNA gene promoter is disrupted by substituting a U6 proximal sequence element A (PSEA) for the U1 PSEA.
Transcription of Drosophila U1 or U6 snRNAs by RNA polymerases II and III respectively requires a unique approximately 21 base-pair promoter element termed the proximal sequence element A (PSEA) recognized by the snRNA activating protein complex (DmSNAPc). A five-nucleotide substitution that changed the U1 PSEA to a U6 PSEA inactivated the U1 promoter. Chromatin immunoprecipitation assays indicated this substitution did not affect DmSNAPc DNA binding but instead interfered with SNAPc recruitment of TBP to the TATA-less U1 promoter. These findings support a model wherein sequence differences between the U1 and U6 PSEAs induce distinct DmSNAPc conformational states involved in RNA polymerase selectivity.
Barakat
Nermeen H
NH
Department of Chemistry and Biochemistry and Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, United States.
Stumph
William E
WE
D000818:Animals; D001665:Binding Sites; D047369:Chromatin Immunoprecipitation; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D009154:Mutation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D012342:RNA, Small Nuclear / Q000235:genetics*; D035181:TATA-Box Binding Protein / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D029721:Drosophila Proteins; D012342:RNA, Small Nuclear; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; C405483:U1 small nuclear RNA; C405486:U6 small nuclear RNA; D012319:RNA Polymerase II