title: The proximal promoter and the start site cooperate to specify correct U1 snRNA transcription initiation by RNA polymerase II.
abstract: In this work, we attempted to gain insight into the detailed mechanism allowing correct transcription initiation of U1 snRNA genes by RNA polymerase II. Abolition of the CA motif residing at -1/+1 in the Xenopus U1 gene leads to a loss of the ability of the promoter to direct accurate initiation. A discrete site is selected only if a purine preceded by a pyrimidine is positioned at 58/57 bp downstream of the center of the PSE. The PSE alone is unable to designate a discrete initiation site. Rather, it serves to set the location of an initiation window without discriminating suitable from unsuitable initiation sites. The latter role is devoted to a PyPu sequence positioned at -1/+1. Therefore, it is the concomitant action of the PSE and an essential PyPu positioned at the proper distance from this promoter that specifies correct U1 snRNA transcription initiation by RNA polymerase II.
authors.affiliation: Unité Structure des Macromolécules Biologiques et Mécanismes de Reconnaissance, CNRS, Strasbourg, France.
authors.forename: A
authors.initials: A
authors.lastname: Lescure
authors.forename: S
authors.initials: S
authors.lastname: Murgo
authors.forename: P
authors.initials: P
authors.lastname: Carbon
authors.forename: A
authors.initials: A
authors.lastname: Krol
mesh_terms: D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D004252:DNA Mutational Analysis; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012319:RNA Polymerase II / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics*; D014982:Xenopus laevis / Q000235:genetics
chemical_list: D012342:RNA, Small Nuclear; D004247:DNA; D012319:RNA Polymerase II