naa a22 4500 528782142 20180924065513.0 cr unu---uuuuu 180924e20140821xx s 000 0 eng 10.3929/ethz-b-000089356 doi 10.1371/journal.pone.0105688 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/89356 Structural and Biochemical Characterization of the Cop9 Signalosome CSN5/CSN6 Heterodimer [Elektronische Daten] [Melissa Birol, Radoslav Ivanov Enchev, André Padilla, Florian Stengel, Ruedi Aebersold, Stéphane Betzi, Yinshan Yang, François Hoh, Matthias Peter, Christian Dumas, Aude Echalier] PLoS ONE Open access ethresearch The Cop9 signalosome complex (CSN) regulates the functional cycle of the major E3 ubiquitin ligase family, the cullin RING E3 ubiquitin ligases (CRLs). Activated CRLs are covalently modified by the ubiquitin-like protein Nedd8 (neural precursor cell expressed developmentally down-regulated protein 8). CSN serves an essential role in myriad cellular processes by reversing this modification through the isopeptidase activity of its CSN5 subunit. CSN5 alone is inactive due to an auto-inhibited conformation of its catalytic domain. Here we report the molecular basis of CSN5 catalytic domain activation and unravel a molecular hierarchy in CSN deneddylation activity. The association of CSN5 and CSN6 MPN (for Mpr1/Pad1 N-terminal) domains activates its isopeptidase activity. The CSN5/CSN6 module, however, is inefficient in CRL deneddylation, indicating a requirement of further elements in this reaction such as other CSN subunits. A hybrid molecular model of CSN5/CSN6 provides a structural framework to explain these functional observations. Docking this model into a published CSN electron density map and using distance constraints obtained from cross-linking coupled to mass-spectrometry, we find that the C-termini of the CSN subunits could form a helical bundle in the centre of the structure. They likely play a key scaffolding role in the spatial organization of CSN and precise positioning of the dimeric MPN catalytic core. Creative Commons Attribution 4.0 International http://creativecommons.org/licenses/by/4.0 ethresearch Birol Melissa joint author Enchev Radoslav Ivanov joint author Padilla André joint author Stengel Florian joint author Aebersold Ruedi joint author Betzi Stéphane joint author Yang Yinshan joint author Hoh François joint author Peter Matthias joint author Dumas Christian joint author Echalier Aude joint author PLoS ONE San Francisco, CA : Public Library of Science 9 (8), p. e105688 1932-6203 http://hdl.handle.net/20.500.11850/89356 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/89356 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Birol Melissa joint author ETHRESEARCH 700 1- Enchev Radoslav Ivanov joint author ETHRESEARCH 700 1- Padilla André joint author ETHRESEARCH 700 1- Stengel Florian joint author ETHRESEARCH 700 1- Aebersold Ruedi joint author ETHRESEARCH 700 1- Betzi Stéphane joint author ETHRESEARCH 700 1- Yang Yinshan joint author ETHRESEARCH 700 1- Hoh François joint author ETHRESEARCH 700 1- Peter Matthias joint author ETHRESEARCH 700 1- Dumas Christian joint author ETHRESEARCH 700 1- Echalier Aude joint author ETHRESEARCH 773 0- PLoS ONE San Francisco, CA : Public Library of Science 9 (8), p. e105688 1932-6203 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access