10
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Functional requirement for symmetric assembly of archaeal box C/D small ribonucleoprotein particles.

      Journal of Molecular Biology
      Archaeal Proteins, chemistry, genetics, metabolism, Archaeoglobus fulgidus, Base Pairing, Base Sequence, Binding Sites, Chromosomal Proteins, Non-Histone, Dimerization, Electrophoretic Mobility Shift Assay, Methylation, Molecular Sequence Data, Mutagenesis, Site-Directed, Nuclear Proteins, RNA Editing, RNA, Archaeal, RNA, Guide, RNA, Small Nucleolar, Ribonucleoproteins, Small Nucleolar

      Read this article at

      ScienceOpenPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Box C/D small ribonucleoprotein particles (sRNPs) are archaeal homologs of small nucleolar ribonucleoprotein particles (snoRNPs) in eukaryotes that are responsible for site specific 2'-O-methylation of ribosomal and transfer RNAs. The function of box C/D sRNPs is characterized by step-wise assembly of three core proteins around a box C/D RNA that include fibrillarin, Nop5p, and L7Ae. The most distinct structural feature in all box C/D RNAs is the presence of two conserved box C/D motifs accompanied by often a single, and sometimes two, antisense elements located immediately upstream of either the D or D' box. Despite this asymmetric distribution of antisense elements, the bipartite feature of the box C/D motifs appears to be in pleasing agreement with a recently reported three-dimensional structure of the core protein complex between fibrillarin and Nop5p. This investigates functional implications of the symmetric features both in box C/D RNAs and in the fibrillarin-Nop5p complex. Site-directed mutagenesis was employed to generate box C/D RNAs lacking one of the two box C/D motifs and a mutant fibrillarin-Nop5p complex deficient in self-association. The ability of the mutated components to assemble and to direct methyl transfer reactions was assessed by gel mobility-shift, analytical ultracentrifugation, and in vitro catalysis studies. The results presented here suggest that, while a box C/D sRNP is capable of asymmetrical assembly, the symmetries in both the box C/D RNA and in the fibrillarin-Nop5p complex are required for efficient catalysis. These findings underscore the importance of functional assembly in methyl transfer reactions.

          Related collections

          Author and article information

          Comments

          Comment on this article