title: An underlying repeat in some transcriptional control sequences corresponding to half a double helical turn of DNA.
abstract: Transcription factor IIIA, which binds to the internal control region of the Xenopus 5S RNA gene has a novel structure consisting of nine tandemly repeated structural units. It was proposed by us that each unit interacts with about 5 bp of DNA. We show here that there is a periodicity on this scale in the DNA sequence and, by fine scale probing with nucleases, a corresponding structural repeat. Similar sequence periodicities are found in the internal control regions of other genes transcribed by RNA polymerase III, and also in the SV40 promoter and a monkey gene region to which the transcription factor Sp1 binds. We propose that transcription factor IIIA is the type of a novel class of transcription factors offering combinatorial possibilities for the specific recognition of DNA.
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003851:Deoxyribonucleases; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism*; D012320:RNA Polymerase III / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014981:Xenopus / Q000235:genetics
chemical_list: D012335:RNA, Ribosomal; D014157:Transcription Factors; D004247:DNA; D012343:RNA, Transfer; D012319:RNA Polymerase II; D012321:DNA-Directed RNA Polymerases; D012320:RNA Polymerase III; D003851:Deoxyribonucleases