Article

Crystal structure and ligand binding of the MID domain of a eukaryotic Argonaute protein.

Department of Biochemistry, Max Planck Institute for Developmental Biology, Spemannstrasse 35, Tübingen D-72076, Germany.
EMBO Reports (impact factor: 7.36). 07/2010; 11(7):522-7. DOI:10.1038/embor.2010.81 pp.522-7
Source: PubMed

ABSTRACT Argonaute (AGO) proteins are core components of RNA-induced silencing complexes and have essential roles in RNA-mediated gene silencing. They are characterized by a bilobal architecture, consisting of one lobe containing the amino-terminal and PAZ domains and another containing the MID and PIWI domains. Except for the PAZ domain, structural information on eukaryotic AGO domains is not yet available. In this study, we report the crystal structure of the MID domain of the eukaryotic AGO protein QDE-2 from Neurospora crassa. This domain adopts a Rossmann-like fold and recognizes the 5'-terminal nucleotide of a guide RNA in a manner similar to its prokaryotic counterparts. The 5'-nucleotide-binding site shares common residues with a second, adjacent ligand-binding site, suggesting a mechanism for the cooperative binding of ligands to the MID domain of eukaryotic AGOs.

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Keywords

5'-nucleotide-binding site shares common residues
 
5'-terminal nucleotide
 
adjacent ligand-binding site
 
complexes
 
crystal structure
 
essential roles
 
guide RNA
 
ligands
 
lobe
 
PIWI domains
 
prokaryotic counterparts
 
RNA-induced
 
RNA-mediated gene
 
structural information