title: A discrete region centered 22 base pairs upstream of the initiation site modulates transcription of Drosophila tRNAAsn genes.
abstract: We have studied the mechanism by which 5'-flanking sequences modulate the in vitro transcription of eucaryotic tRNA genes. Using deletion and linker substitution mutagenesis, we have found that the 5'-flanking sequences responsible for the different in vitro transcription levels of three Drosophila tRNA5Asn genes are contained within a discrete region centered 22 nucleotides upstream from the transcription initiation site. In conjunction with the A-box intragenic control region, this upstream transcription-modulatory region functions in the selection mechanism for the site of transcription initiation. Since the transcription-modulatory region directs the position of the start site and the actual sequence of the transcription-modulatory region determines the level of tRNAAsn gene transcription, the possibility is raised that the transcription-modulatory region directs a transcription initiation event similar to open complex formation at procaryotic promoters.
mesh_terms: D000818:Animals; D001483:Base Sequence; D004252:DNA Mutational Analysis; D004331:Drosophila melanogaster / Q000235:genetics*; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000378:metabolism; D012345:RNA, Transfer, Amino Acid-Specific / Q000235:genetics*; D012348:RNA, Transfer, Asn / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D012345:RNA, Transfer, Amino Acid-Specific; D012348:RNA, Transfer, Asn; D012320:RNA Polymerase III