1yvu

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spinqualitylabelsall models 1yvu, resolution 2.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of A. aeolicus Argonaute

Overview

Argonaute (Ago) proteins constitute a key component of the RNA-induced, silencing complex (RISC). We report the crystal structure of Aquifex, aeolicus Ago (Aa-Ago) together with binding and cleavage studies, which, establish this eubacterial Ago as a bona fide guide DNA strand-mediated, site-specific RNA endonuclease. We have generated a stereochemically, robust model of the complex, where the guide DNA-mRNA duplex is positioned, within a basic channel spanning the bilobal interface, such that the 5', phosphate of the guide strand can be anchored in a basic pocket, and the, mRNA can be positioned for site-specific cleavage by RNase H-type divalent, cation-coordinated catalytic Asp residues of the PIWI domain. Domain swap, experiments involving chimeras of human Ago (hAgo1) and cleavage-competent, hAgo2 reinforce the role of the PIWI domain in "slicer" activity. We, propose a four-step Ago-mediated catalytic cleavage cycle model, which, provides distinct perspectives into the mechanism of guide strand-mediated, mRNA cleavage within the RISC.

About this Structure

1YVU is a Single protein structure of sequence from Aquifex aeolicus vf5 with CA as ligand. Full crystallographic information is available from OCA.

Reference

Crystal structure of A. aeolicus argonaute, a site-specific DNA-guided endoribonuclease, provides insights into RISC-mediated mRNA cleavage., Yuan YR, Pei Y, Ma JB, Kuryavyi V, Zhadina M, Meister G, Chen HY, Dauter Z, Tuschl T, Patel DJ, Mol Cell. 2005 Aug 5;19(3):405-19. PMID:16061186

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