title: The 5' end of U2 snRNA is in close proximity to U1 and functional sites of the pre-mRNA in early spliceosomal complexes.
abstract: Recognition and pairing of the correct 5' and 3' splice sites (ss) of a pre-mRNA are critical events that occur early during spliceosome assembly. Little is known about the spatial organization in early spliceosomal complexes of the U1 and U2 snRNPs, which together with several non-snRNP proteins, are involved in juxtapositioning the functional sites of the pre-mRNA. To better understand the molecular mechanisms of splice-site recognition/pairing, we have examined the organization of U2 relative to U1 and pre-mRNA in spliceosomal complexes via hydroxyl-radical probing with Fe-BABE-tethered U2 snRNA. These studies reveal that functional sites of the pre-mRNA are located close to the 5' end of U2 both in E and A complexes. U2 is also positioned close to U1 in a defined orientation already in the E complex, and their relative spatial organization remains largely unchanged during the E to A transition.
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Gizem
authors.initials: G
authors.lastname: Dönmez
authors.forename: Klaus
authors.initials: K
authors.lastname: Hartmuth
authors.forename: Berthold
authors.initials: B
authors.lastname: Kastner
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Will
authors.forename: Reinhard
authors.initials: R
authors.lastname: Lührmann
mesh_terms: D004492:Edetic Acid / Q000031:analogs & derivatives / Q000032:analysis; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000378:metabolism*; D022821:RNA Splice Sites; D012326:RNA Splicing / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000737:chemistry* / Q000378:metabolism; D017381:Spliceosomes / Q000737:chemistry* / Q000378:metabolism
chemical_list: D012322:RNA Precursors; D022821:RNA Splice Sites; D012333:RNA, Messenger; D012342:RNA, Small Nuclear; C405483:U1 small nuclear RNA; C405484:U2 small nuclear RNA; C042007:1-(4-bromoacetamidobenzyl)EDTA; D004492:Edetic Acid