Functional association of U2 snRNP with the ATP-independent spliceosomal complex E

Mol Cell. 2000 May;5(5):779-87. doi: 10.1016/s1097-2765(00)80318-4.

Abstract

In the current model for spliceosome assembly, U1 snRNP binds to the 5' splice site in the E complex followed by ATP-dependent binding of U2 snRNP to the branchpoint sequence (BPS) in the A complex. Here we report the characterization of highly purified, functional E complex. We provide evidence that this complex contains functional U2 snRNP and that this snRNP is required for E complex assembly. The BPS is not required for U2 snRNP binding in the E complex. These data suggest a model for spliceosome assembly in which U1 and U2 snRNPs first associate with the spliceosome in the E complex and then an ATP-dependent step results in highly stable U2 snRNP binding to the BPS in the A complex.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases
  • Adenosine Triphosphate / metabolism
  • DEAD-box RNA Helicases
  • Macromolecular Substances
  • Models, Structural
  • Nucleic Acid Conformation
  • RNA Splicing Factors
  • RNA-Binding Proteins / metabolism
  • Ribonucleoprotein, U1 Small Nuclear / metabolism
  • Ribonucleoprotein, U2 Small Nuclear / metabolism*
  • Spliceosomes / metabolism*

Substances

  • Macromolecular Substances
  • RNA Splicing Factors
  • RNA-Binding Proteins
  • Ribonucleoprotein, U1 Small Nuclear
  • Ribonucleoprotein, U2 Small Nuclear
  • splicing factor 3a
  • Adenosine Triphosphate
  • Adenosine Triphosphatases
  • DHX38 protein, human
  • DEAD-box RNA Helicases