Structural Basis for Substrate Placement by an Archaeal Box C/D Ribonucleoprotein Particle

Journal Article · Wed May 09 04:00:00 EDT 2012 · Mol. Cell

DOI:https://doi.org/10.1016/j.molcel.2010.08.022· OSTI ID:1034180

Xue, Song; Wang, Ruiying; Yang, Fangping; Terns, Rebecca M; Terns, Michael P; Zhang, Xinxin; Maxwell, E Stuart; Li, Hong ^[1]

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1. NCSU

Box C/D small nucleolar and Cajal body ribonucleoprotein particles (sno/scaRNPs) direct site-specific 2'-O-methylation of ribosomal and spliceosomal RNAs and are critical for gene expression. Here we report crystal structures of an archaeal box C/D RNP containing three core proteins (fibrillarin, Nop56/58, and L7Ae) and a half-mer box C/D guide RNA paired with a substrate RNA. The structure reveals a guide-substrate RNA duplex orientation imposed by a composite protein surface and the conserved GAEK motif of Nop56/58. Molecular modeling supports a dual C/D RNP structure that closely mimics that recently visualized by electron microscopy. The substrate-bound dual RNP model predicts an asymmetric protein distribution between the RNP that binds and methylates the substrate RNA. The predicted asymmetric nature of the holoenzyme is consistent with previous biochemical data on RNP assembly and provides a simple solution for accommodating base-pairing between the C/D guide RNA and large ribosomal and spliceosomal substrate RNAs.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: AHANSFNIH
• OSTI ID: 1034180
• Journal Information: Mol. Cell, Journal Name: Mol. Cell Journal Issue: (6) ; 09, 2010 Vol. 39
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
CRYSTAL STRUCTURE
DISTRIBUTION
ELECTRON MICROSCOPY
GENES
ORIENTATION
PROTEINS
RNA
SIMULATION
SUBSTRATES