title: Two-step affinity purification of U7 small nuclear ribonucleoprotein particles using complementary biotinylated 2'-O-methyl oligoribonucleotides.
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).
authors.affiliation: Research Institute of Molecular Pathology, Vienna, Austria.
authors.forename: H O
authors.initials: HO
authors.lastname: Smith
authors.forename: K
authors.initials: K
authors.lastname: Tabiti
authors.forename: G
authors.initials: G
authors.lastname: Schaffner
authors.forename: D
authors.initials: D
authors.lastname: Soldati
authors.forename: U
authors.initials: U
authors.lastname: Albrecht
authors.forename: M L
authors.initials: ML
authors.lastname: Birnstiel
mesh_terms: D000818:Animals; D001483:Base Sequence; D001710:Biotin; D002467:Cell Nucleus / Q000737:chemistry; D002846:Chromatography, Affinity; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry; D012261:Ribonucleoproteins / Q000737:chemistry / Q000302:isolation & purification*; D017411:Ribonucleoproteins, Small Nuclear
chemical_list: D009841:Oligonucleotides; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D001710:Biotin