title: The human immunodeficiency virus type 1 long terminal repeat specifies two different transcription complexes, only one of which is regulated by Tat.
abstract: The human immunodeficiency virus type 1 long terminal repeat sets up two different transcription complexes, which have been called processive and nonprocessive complexes. By mutating and substituting cis-acting sequences, we mapped elements of the human immunodeficiency virus long terminal repeat that are responsible for creating each transcription complex. Whereas processive complexes are efficiently assembled by upstream promoter elements in the absence of the TATA box, nonprocessive complexes absolutely require the TATA box. Moreover, the TATA box alone can set up these nonprocessive complexes, and nonprocessive but not processive complexes are trans activated by Tat. Finally, a strong DNA-binding site between the TATA box and trans-activation-responsive region interferes with either the assembly or movement of these nonprocessive complexes and diminishes the effects of Tat. Thus, Tat affects a critical step in the formation of elongation-competent transcription complexes.
authors.affiliation: Howard Hughes Medical Institute, University of California, San Francisco 94143-0724.
authors.forename: X
authors.initials: X
authors.lastname: Lu
authors.forename: T M
authors.initials: TM
authors.lastname: Welsh
authors.forename: B M
authors.initials: BM
authors.lastname: Peterlin
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004279:DNA, Viral / Q000235:genetics; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D015696:Gene Products, tat / Q000235:genetics*; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000378:metabolism; D016385:TATA Box; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D004279:DNA, Viral; D015696:Gene Products, tat; D009838:Oligodeoxyribonucleotides; D016329:Sp1 Transcription Factor; D054322:tat Gene Products, Human Immunodeficiency Virus; D012319:RNA Polymerase II