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Using Cryo‐electron Microscopy to Discover Box C/D s(no)RNP Structure
Author(s) -
Baserga Susan J,
Yip W.S. Vincent,
Shigematsu Hideki,
Taylor David W.
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.910.2
Subject(s) - ribosomal rna , ribonucleoprotein , archaea , cryo electron microscopy , ribosome , rna , biology , function (biology) , microbiology and biotechnology , biophysics , computational biology , chemistry , genetics , bacteria , gene
Ribosomal RNA (rRNA) modifications are essential for ribosome function in all cellular organisms. Box C/D small (nucleolar) ribonucleoproteins [s(no)RNPs] catalyze 2′‐ O ‐methylation, one type of rRNA modification found in Eukarya and Archaea. Negatively stained electron microscopy (EM) models of archaeal box C/D sRNPs from our laboratory have demonstrated the dimeric sRNP (di‐sRNP) architecture, which has been corroborated by nuclear magnetic resonance (NMR) studies. Because of the limitations of the structural techniques, the orientation of the box C/D sRNAs in the di‐sRNP has remained unclear. Here, we have used cryo‐EM to elucidate the orientation of the sRNAs in a M. jannaschii box C/D di‐sRNP. The cryo‐EM reconstruction suggests a parallel orientation of the two sRNAs. This is further confirmed by results from biochemical and structural analyses of sRNPs assembled with mutant sRNAs that indicate a potential interaction between the sRNA stem ends. Our results suggest that the parallel arrangement of the sRNAs juxtaposes their stem ends into close proximity to allow for a stabilizing interaction that helps maintain the di‐sRNP architecture. Support or Funding Information Supported by NIH R01GM0115710