Two-step affinity purification of U7 small nuclear ribonucleoprotein particles using complementary biotinylated 2'-O-methyl oligoribonucleotides

Proc Natl Acad Sci U S A. 1991 Nov 1;88(21):9784-8. doi: 10.1073/pnas.88.21.9784.

Abstract

U7 snRNP is a low-abundance small nuclear ribonucleoprotein particle essential for 3' processing of replication-dependent histone pre-mRNA. We have developed a two-step purification of the particle from TB21 mouse mastocytoma cell nuclear extracts, with about a 20% overall yield, using affinity binding to 2'-O-methyl oligoribonucleotides. The purified particle is homogeneous with respect to RNA content. SDS/PAGE of the U7 snRNP proteins revealed a full complement of the standard core proteins (B, DD', E, F, and G) found in the majority of snRNPs. In addition, two U7-specific polypeptides of 14 kDa and 50 kDa were identified. Summation of the molecular masses of the identified components of the U7 particle yields a particle mass of 249 kDa, in approximate agreement with estimates from sucrose gradient sedimentation (261 kDa) and nondenaturing gradient PAGE (217 kDa).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Biotin
  • Cell Nucleus / chemistry
  • Chromatography, Affinity
  • Mice
  • Molecular Sequence Data
  • Molecular Weight
  • Nucleic Acid Hybridization
  • Oligonucleotides / chemistry
  • Ribonucleoproteins / chemistry
  • Ribonucleoproteins / isolation & purification*
  • Ribonucleoproteins, Small Nuclear

Substances

  • Oligonucleotides
  • Ribonucleoproteins
  • Ribonucleoproteins, Small Nuclear
  • Biotin