title: Structure of Rpn10 and its interactions with polyubiquitin chains and the proteasome subunit Rpn12.
abstract: Schizosaccharomyces pombe Rpn10 (SpRpn10) is a proteasomal ubiquitin (Ub) receptor located within the 19 S regulatory particle where it binds to subunits of both the base and lid subparticles. We have solved the structure of full-length SpRpn10 by determining the crystal structure of the von Willebrand factor type A domain and characterizing the full-length protein by NMR. We demonstrate that the single Ub-interacting motif (UIM) of SpRpn10 forms a 1:1 complex with Lys(48)-linked diUb, which it binds selectively over monoUb and Lys(63)-linked diUb. We further show that the SpRpn10 UIM binds to SpRpn12, a subunit of the lid subparticle, with an affinity comparable with Lys(48)-linked diUb. This is the first observation of a UIM binding other than a Ub fold and suggests that SpRpn12 could modulate the activity of SpRpn10 as a proteasomal Ub receptor.
authors.affiliation: Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Christiane
authors.initials: C
authors.lastname: Riedinger
authors.forename: Jonas
authors.initials: J
authors.lastname: Boehringer
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Trempe
authors.forename: Edward D
authors.initials: ED
authors.lastname: Lowe
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Brown
authors.forename: Kalle
authors.initials: K
authors.lastname: Gehring
authors.forename: Martin E M
authors.initials: ME
authors.lastname: Noble
authors.forename: Colin
authors.initials: C
authors.lastname: Gordon
authors.forename: Jane A
authors.initials: JA
authors.lastname: Endicott
mesh_terms: D002151:Calorimetry / Q000379:methods; D002352:Carrier Proteins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008239:Lysine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D025821:Polyubiquitin / Q000737:chemistry*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011485:Protein Binding; D016601:RNA-Binding Proteins; D012568:Schizosaccharomyces / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*; D015398:Signal Transduction; D020349:Surface Plasmon Resonance; D025801:Ubiquitin / Q000737:chemistry; D014841:von Willebrand Factor / Q000737:chemistry
chemical_list: D002352:Carrier Proteins; D016601:RNA-Binding Proteins; C098743:RPN12 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D025801:Ubiquitin; C498507:pus1 protein, S pombe; D014841:von Willebrand Factor; D025821:Polyubiquitin; D046988:Proteasome Endopeptidase Complex; D008239:Lysine