title: The branch site adenosine is recognized differently for the two steps of pre-mRNA splicing.
abstract: The functional groups responsible for branch site identity in the two steps of pre-mRNA splicing as well as for spliceosome assembly were tested by incorporation of site-specific modifications at the branch site of a pre-mRNA. These results show that recognition of the adenosine occurs early in complex formation and that the branch site adenosine is recognized differently before the first step and for the second step. Further, direct UV cross-linking with these modified RNAs was used to identify a factor whose interaction was dependent upon the identity of the branch site nucleotide.
authors.affiliation: Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139-4307, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Query
authors.forename: S A
authors.initials: SA
authors.lastname: Strobel
authors.forename: P A
authors.initials: PA
authors.lastname: Sharp
mesh_terms: D000241:Adenosine / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003432:Cross-Linking Reagents; D015394:Molecular Structure; D012322:RNA Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000378:metabolism; D017381:Spliceosomes / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D012322:RNA Precursors; D012331:RNA, Fungal; D017413:Ribonucleoprotein, U2 Small Nuclear; D000241:Adenosine