title: TATA-binding protein and transcription factor IIB induce transcript slipping during early transcription by RNA polymerase II.
abstract: To better understand the mechanism of steps in early transcription by RNA polymerase II (pol II), we investigated the molecular determinants of transcript slipping within complexes assembled on promoters containing a pre-melted transcription bubble from -9 to +3. Transcript slippage occurs when an RNA transcript contains a repetitive sequence that allows the transcript to slip back and pair with the template strand of the DNA at a new register before transcription continues. We established the contributions of individual transcription factors, DNA elements, and RNA length to slipping on a heteroduplex template using a highly purified human pol II transcription system. We found that transcripts slip at a very defined point in the transcription reaction, after pol II completes phosphodiester bond synthesis at register +5. This point is set by the position of the polymerase active site on the DNA template, as opposed to the length of the transcript, as well as by a repetitive CUCU sequence that must occur from +2 to +5. Interestingly, slipping at this juncture is induced by TATA-binding protein and transcription factor IIB and requires a TATA box but not a transcription factor IIB recognition sequence. We propose a model in which transcribing complexes, upon completing phosphodiester bond synthesis at register +5, enter one of two branches in which they either complete productive synthesis of the transcript or undergo multiple rounds of transcript slipping.
authors.affiliation: Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gilman
authors.forename: Linda F
authors.initials: LF
authors.lastname: Drullinger
authors.forename: Jennifer F
authors.initials: JF
authors.lastname: Kugel
authors.forename: James A
authors.initials: JA
authors.lastname: Goodrich
mesh_terms: D001483:Base Sequence; D020134:Catalytic Domain; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004951:Esterification; D006801:Humans; D008969:Molecular Sequence Data; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000235:genetics / Q000378:metabolism*; D013698:Templates, Genetic; D013997:Time Factors; D035581:Transcription Factor TFIIB / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D004247:DNA; D012319:RNA Polymerase II