Abstract
The box C/D snoRNAs function in directing 2'-O-methylation and/or as chaperones in the processing of ribosomal RNA. We show here that Snu13p (15.5 kD in human), a component of the U4/U6.U5 tri-snRNP, is also associated with the box C/D snoRNAs. Indeed, genetic depletion of Snu13p in yeast leads to a major defect in RNA metabolism. The box C/D motif can be folded into a stem-internal loop-stem structure, almost identical to the 15.5 kD binding site in the U4 snRNA. Consistent with this, the box C/D motif binds Snu13p/ 15.5 kD in vitro. The similarities in structure and function observed between the U4 snRNP (chaperone for U6) and the box C/D snoRNPs raises the interesting possibility that these particles may have evolved from a common ancestral RNP.
Publication types
- Research Support, Non-U.S. Gov't
MeSH terms
- Base Sequence
- Binding Sites
- Evolution, Molecular*
- Fungal Proteins / genetics
- Fungal Proteins / metabolism
- Gene Deletion
- HeLa Cells
- Humans
- Molecular Weight
- Nucleic Acid Conformation
- Precipitin Tests
- Protein Binding
- RNA, Fungal / chemistry
- RNA, Fungal / genetics
- RNA, Fungal / metabolism
- RNA, Small Nuclear / chemistry
- RNA, Small Nuclear / genetics
- RNA, Small Nuclear / metabolism
- RNA, Small Nucleolar / chemistry
- RNA, Small Nucleolar / genetics
- RNA, Small Nucleolar / metabolism
- RNA-Binding Proteins / genetics
- RNA-Binding Proteins / metabolism*
- Recombinant Proteins
- Regulatory Sequences, Nucleic Acid / genetics
- Ribonucleoprotein, U4-U6 Small Nuclear / chemistry*
- Ribonucleoprotein, U4-U6 Small Nuclear / genetics
- Ribonucleoprotein, U4-U6 Small Nuclear / metabolism
- Ribonucleoproteins, Small Nucleolar / chemistry*
- Ribonucleoproteins, Small Nucleolar / genetics
- Ribonucleoproteins, Small Nucleolar / isolation & purification
- Ribonucleoproteins, Small Nucleolar / metabolism
- Spliceosomes / chemistry*
- Spliceosomes / genetics
- Substrate Specificity
- Yeasts / genetics
- Yeasts / metabolism*
Substances
- Fungal Proteins
- RNA, Fungal
- RNA, Small Nuclear
- RNA, Small Nucleolar
- RNA, U3 small nucleolar
- RNA-Binding Proteins
- Recombinant Proteins
- Ribonucleoprotein, U4-U6 Small Nuclear
- Ribonucleoproteins, Small Nucleolar
- U4 small nuclear RNA
- ribonucleoprotein, U3 small nucleolar