3RIU

Crystal structure of Drosophila hexameric C3PO formed by truncated Translin and Trax

Summary for 3RIU

• Entry DOI: 10.2210/pdb3riu/pdb
• Descriptor: Translin, Translin associated factor X, isoform B (2 entities in total)
• Functional Keywords: translin-fold, ribonuclease, risc activator, nucleus, hydrolase
• Biological source: Drosophila melanogaster (Fruit fly); More
• Total number of polymer chains: 3
• Total formula weight: 82100.70

Authors

Tian, Y.,Simanshu, D.K.,Patel, D.J. (deposition date: 2011-04-14, release date: 2011-05-11, Last modification date: 2017-11-08)

Primary citation

Tian, Y.,Simanshu, D.K.,Ascano, M.,Diaz-Avalos, R.,Park, A.Y.,Juranek, S.A.,Rice, W.J.,Yin, Q.,Robinson, C.V.,Tuschl, T.,Patel, D.J.
Multimeric assembly and biochemical characterization of the Trax-translin endonuclease complex.
Nat.Struct.Mol.Biol., 18:658-664, 2011

PubMed Abstract: Trax-translin heteromers, also known as C3PO, have been proposed to activate the RNA-induced silencing complex (RISC) by facilitating endonucleolytic cleavage of the siRNA passenger strand. We report on the crystal structure of hexameric Drosophila C3PO formed by truncated translin and Trax, along with electron microscopic and mass spectrometric studies on octameric C3PO formed by full-length translin and Trax. Our studies establish that Trax adopts the translin fold, possesses catalytic centers essential for C3PO's endoRNase activity and interacts extensively with translin to form an octameric assembly. The catalytic pockets of Trax subunits are located within the interior chamber of the octameric scaffold. Truncated C3PO, like full-length C3PO, shows endoRNase activity that leaves 3'-hydroxyl-cleaved ends. We have measured the catalytic activity of C3PO and shown it to cleave almost stoichiometric amounts of substrate per second.

PubMed: 21552261
DOI: 10.1038/nsmb.2069

Experimental method

X-RAY DIFFRACTION (3.4 Å)