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.
Department of Chemistry and Biochemistry and Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, United States.
Nermeen H
NH
Barakat
William E
WE
Stumph
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