Download MendeleySculpting of the Spliceosomal Branch Site Recognition Motif by a Conserved Pseudouridine
Newby, M.I., Greenbaum, N.L.(2002) Nat Struct Biol 9: 958-965
- PubMed: 12426583
- DOI: https://doi.org/10.1038/nsb873
- Primary Citation of Related Structures:
1LMV, 1LPW - PubMed Abstract:
Pairing of a consensus sequence of the precursor (pre)-mRNA intron with a short region of the U2 small nuclear (sn)RNA during assembly of the eukaryotic spliceosome results in formation of a complementary helix of seven base pairs with a single unpaired adenosine residue. The 2' OH of this adenosine, called the branch site, brings about nucleophilic attack at the pre-mRNA 5' splice site in the first step of splicing. Another feature of this pairing is the phylogenetic conservation of a pseudouridine (psi) residue in U2 snRNA nearly opposite the branch site. We show that the presence of this psi in the pre-mRNA branch-site helix of Saccharomyces cerevisiae induces a dramatically altered architectural landscape compared with that of its unmodified counterpart. The psi-induced structure places the nucleophile in an accessible position for the first step of splicing.
Organizational Affiliation:
Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4390, USA.
