title: Tfb6, a previously unidentified subunit of the general transcription factor TFIIH, facilitates dissociation of Ssl2 helicase after transcription initiation.
abstract: General transcription factor TFIIH, previously described as a 10-subunit complex, is essential for transcription and DNA repair. An eleventh subunit now identified, termed Tfb6, exhibits 45% sequence similarity to human nuclear mRNA export factor 5. Tfb6 dissociates from TFIIH as a heterodimer with the Ssl2 subunit, a DNA helicase that drives promoter melting for the initiation of transcription. Tfb6 does not, however, dissociate Ssl2 from TFIIH in the context of a fully assembled transcription preinitiation complex. Our findings suggest a dynamic state of Ssl2, allowing its engagement in multiple cellular processes.
authors.affiliation: Department of Structural Biology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Kenji
authors.initials: K
authors.lastname: Murakami
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Gibbons
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Davis
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nagai
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Philip J J
authors.initials: PJ
authors.lastname: Robinson
authors.forename: Tinghe
authors.initials: T
authors.lastname: Wu
authors.forename: Craig D
authors.initials: CD
authors.lastname: Kaplan
authors.forename: Roger D
authors.initials: RD
authors.lastname: Kornberg
mesh_terms: D002853:Chromatography, Liquid; D004265:DNA Helicases / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000528:radiation effects; D006801:Humans; D013058:Mass Spectrometry; D010641:Phenotype; D010766:Phosphorylation / Q000528:radiation effects; D011485:Protein Binding / Q000528:radiation effects; D021122:Protein Subunits / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature; D051758:Transcription Factor TFIIH / Q000737:chemistry / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D021122:Protein Subunits; D012333:RNA, Messenger; C489575:SSL2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C572245:Tfb6 protein, S cerevisiae; D014157:Transcription Factors; D051758:Transcription Factor TFIIH; D004265:DNA Helicases