Crystal structure of the spliceosomal U2B"-U2A' protein complex bound to a fragment of U2 small nuclear RNA

Nature. 1998 Aug 13;394(6694):645-50. doi: 10.1038/29234.


We have determined the crystal structure at 2.4 A resolution of a ternary complex between the spliceosomal U2B"/U2A' protein complex and hairpin-loop IV of U2 small nuclear RNA. Unlike its close homologue the U1A protein, U2B" binds to its cognate RNA only in the presence of U2A', which contains leucine-rich repeats in its sequence. The concave surface of a parallel beta-sheet within the leucine-rich-repeat region of U2A' interacts with the ribonucleoprotein domain of U2B" on the surface opposite its RNA-binding surface. The basic carboxy-terminal region of U2A' interacts with the RNA stem. The crystal structure reveals how protein-protein interaction regulates RNA-binding specificity, and how replacing only a few key residues allows the U2B" and U1A proteins to discriminate between their cognate RNA hairpins by forming alternative networks of interactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Autoantigens
  • Crystallography, X-Ray
  • Drosophila
  • Drosophila Proteins*
  • Evolution, Molecular
  • Humans
  • Leucine-Rich Repeat Proteins
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Protein Binding
  • Protein Conformation
  • Proteins / chemistry
  • RNA, Small Nuclear / chemistry*
  • RNA, Small Nuclear / metabolism
  • RNA-Binding Proteins*
  • Recombinant Proteins / chemistry
  • Ribonucleoprotein, U1 Small Nuclear / chemistry
  • Ribonucleoprotein, U2 Small Nuclear / chemistry*
  • Ribonucleoprotein, U2 Small Nuclear / metabolism
  • Ribonucleoproteins, Small Nuclear
  • snRNP Core Proteins


  • Autoantigens
  • Drosophila Proteins
  • Leucine-Rich Repeat Proteins
  • Proteins
  • RNA, Small Nuclear
  • RNA-Binding Proteins
  • Recombinant Proteins
  • Ribonucleoprotein, U1 Small Nuclear
  • Ribonucleoprotein, U2 Small Nuclear
  • Ribonucleoproteins, Small Nuclear
  • SNRPB2 protein, human
  • U2A protein, Drosophila
  • U2A' protein, human
  • snRNP Core Proteins
  • snf protein, Drosophila

Associated data

  • PDB/1A9N