Structure of the yeast U2/U6 snRNA complex

RNA. 2012 Apr;18(4):673-83. doi: 10.1261/rna.031138.111. Epub 2012 Feb 10.

Abstract

The U2/U6 snRNA complex is a conserved and essential component of the active spliceosome that interacts with the pre-mRNA substrate and essential protein splicing factors to promote splicing catalysis. Here we have elucidated the solution structure of a 111-nucleotide U2/U6 complex using an approach that integrates SAXS, NMR, and molecular modeling. The U2/U6 structure contains a three-helix junction that forms an extended "Y" shape. The U6 internal stem-loop (ISL) forms a continuous stack with U2/U6 Helices Ib, Ia, and III. The coaxial stacking of Helix Ib on the U6 ISL is a configuration that is similar to the Domain V structure in group II introns. Interestingly, essential features of the complex--including the U80 metal binding site, AGC triad, and pre-mRNA recognition sites--localize to one face of the molecule. This observation suggests that the U2/U6 structure is well-suited for orienting substrate and cofactors during splicing catalysis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Nuclear Magnetic Resonance, Biomolecular
  • Nucleic Acid Conformation*
  • RNA, Fungal / chemistry*
  • RNA, Small Nuclear / chemistry*
  • Saccharomyces cerevisiae / genetics*

Substances

  • RNA, Fungal
  • RNA, Small Nuclear
  • U2 small nuclear RNA
  • U6 small nuclear RNA

Associated data

  • PDB/2LK3
  • PDB/2LKR