2f8s
From Proteopedia
Crystal structure of Aa-Ago with externally-bound siRNA
Overview
Argonaute proteins are key components of the RNA-induced silencing complex (RISC). They provide both architectural and catalytic functionalities associated with small interfering RNA (siRNA) guide strand recognition and subsequent guide strand-mediated cleavage of complementary mRNAs. We report on the 3.0 A crystal structures of 22-mer and 26-mer siRNAs bound to Aquifex aeolicus Argonaute (Aa-Ago), where one 2 nt 3' overhang of the siRNA inserts into a cavity positioned on the outer surface of the PAZ-containing lobe of the bilobal Aa-Ago architecture. The first overhang nucleotide stacks over a tyrosine ring, while the second overhang nucleotide, together with the intervening sugar-phosphate backbone, inserts into a preformed surface cavity. Photochemical crosslinking studies on Aa-Ago with 5-iodoU-labeled single-stranded siRNA and siRNA duplex provide support for this externally bound siRNA-Aa-Ago complex. The structure and biochemical data together provide insights into a protein-RNA recognition event potentially associated with the RISC-loading pathway.
About this Structure
2F8S is a Single protein structure of sequence from Aquifex aeolicus. Full crystallographic information is available from OCA.
Reference
A potential protein-RNA recognition event along the RISC-loading pathway from the structure of A. aeolicus Argonaute with externally bound siRNA., Yuan YR, Pei Y, Chen HY, Tuschl T, Patel DJ, Structure. 2006 Oct;14(10):1557-65. PMID:17027504 Page seeded by OCA on Sun May 4 03:35:58 2008
