We have updated our privacy policy. If you have any question, contact us at privacy@scicrunch.org. Dismiss and don't show again

Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Crystal structure of A. aeolicus argonaute, a site-specific DNA-guided endoribonuclease, provides insights into RISC-mediated mRNA cleavage.

Molecular cell | Aug 5, 2005

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.

Pubmed ID: 16061186 RIS Download

Mesh terms: Amino Acid Sequence | Argonaute Proteins | Bacteria | Bacterial Proteins | Binding Sites | Catalytic Domain | Cations, Divalent | Crystallography, X-Ray | DNA, Single-Stranded | Endoribonucleases | Eukaryotic Initiation Factor-2 | Eukaryotic Initiation Factors | Humans | Models, Chemical | Models, Molecular | Molecular Sequence Data | Oligonucleotides | Peptide Initiation Factors | Protein Binding | Protein Conformation | Protein Structure, Tertiary | RNA, Double-Stranded | RNA, Messenger | RNA-Induced Silencing Complex | Recombinant Fusion Proteins | Recombinant Proteins | Sequence Homology, Amino Acid | Static Electricity

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

None found

Associated grants

  • Agency: NCI NIH HHS, Id: P30 CA008748
  • Agency: NIAID NIH HHS, Id: R01 AI068776
  • Agency: NIGMS NIH HHS, Id: R01 GM068476
  • Agency: NIGMS NIH HHS, Id: R01 GM068476-01

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.