title: A U1 snRNA:pre-mRNA base pairing interaction is required early in yeast spliceosome assembly but does not uniquely define the 5' cleavage site.
abstract: We analyzed the effects of suppressor mutations in the U1 snRNA (SNR19) gene from Saccharomyces cerevisiae on the splicing of mutant pre-mRNA substrates. The results indicate that pairing between U1 snRNA and the highly conserved position 5 (GTATGT) of the intron occurs early in spliceosome assembly in vitro. This pairing is important for efficient splicing both in vitro and in vivo. However, pairing at position 5 does not appear to influence 5' splice site selection in vivo, indicating that the previously described U1 snRNA:5' splice junction base pairing interaction is not sufficient to define the 5' cleavage site.
authors.affiliation: Department of Biology, Brandeis University, Waltham, MA 02254.
authors.forename: B
authors.initials: B
authors.lastname: Séraphin
authors.forename: L
authors.initials: L
authors.lastname: Kretzner
authors.forename: M
authors.initials: M
authors.lastname: Rosbash
mesh_terms: D007438:Introns; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics*; D012342:RNA, Small Nuclear / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013489:Suppression, Genetic
chemical_list: D012322:RNA Precursors; D012333:RNA, Messenger; D012342:RNA, Small Nuclear