Download MendeleyCrystal structure of A. aeolicus Argonaute provides unique perspectives into the mechanism of guide strand-mediated mRNA cleavage
Yuan, Y.R., Pei, Y., Ma, J.B., Kuryavyi, V., Zhadina, M., Meister, G., Chen, H.Y., Dauter, Z., Tuschl, T., Patel, D.J.(2005) Mol Cell 19: 405-419
- PubMed: 16061186
- DOI: https://doi.org/10.1016/j.molcel.2005.07.011
- Primary Citation of Related Structures:
1YVU - PubMed Abstract:
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.
Organizational Affiliation:
Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
