1u04
Crystal structure of full length Argonaute from Pyrococcus furiosus
OverviewOverview
Argonaute proteins and small interfering RNAs (siRNAs) are the known signature components of the RNA interference effector complex RNA-induced silencing complex (RISC). However, the identity of "Slicer," the enzyme that cleaves the messenger RNA (mRNA) as directed by the siRNA, has not been resolved. Here, we report the crystal structure of the Argonaute protein from Pyrococcus furiosus at 2.25 angstrom resolution. The structure reveals a crescent-shaped base made up of the amino-terminal, middle, and PIWI domains. The Piwi Argonaute Zwille (PAZ) domain is held above the base by a "stalk"-like region. The PIWI domain (named for the protein piwi) is similar to ribonuclease H, with a conserved active site aspartate-aspartate-glutamate motif, strongly implicating Argonaute as "Slicer." The architecture of the molecule and the placement of the PAZ and PIWI domains define a groove for substrate binding and suggest a mechanism for siRNA-guided mRNA cleavage.
About this StructureAbout this Structure
1U04 is a Single protein structure of sequence from Pyrococcus furiosus dsm 3638. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of Argonaute and its implications for RISC slicer activity., Song JJ, Smith SK, Hannon GJ, Joshua-Tor L, Science. 2004 Sep 3;305(5689):1434-7. Epub 2004 Jul 29. PMID:15284453 Page seeded by OCA on Sat May 3 10:34:55 2008