title: Molecular basis for bre5 cofactor recognition by the ubp3 deubiquitylating enzyme.
abstract: Yeast Ubp3 and its co-factor Bre5 form a deubiquitylation complex to regulate protein transport between the endoplasmic reticulum and Golgi compartments of the cell. A novel N-terminal domain of the Ubp3 catalytic subunit forms a complex with the NTF2-like domain of the Bre5 regulatory subunit. Here, we report the X-ray crystal structure of an Ubp3-Bre5 complex and show that it forms a symmetric hetero-tetrameric complex in which the Bre5 NTF2-like domain dimer interacts with two L-shaped beta-strand-turn-alpha-helix motifs of Ubp3. The Ubp3 N-terminal domain binds within a hydrophobic cavity on the surface of the Bre5 NTF2-like domain subunit with conserved residues within both proteins interacting predominantly through antiparallel beta-sheet hydrogen bonds and van der Waals contacts. Structure-based mutagenesis and functional studies confirm the significance of the observed interactions for Ubp3-Bre5 association in vitro and Ubp3 function in vivo. Comparison of the structure to other protein complexes with NTF2-like domains shows that the Ubp3-Bre5 interface is novel. Together, these studies provide new insights into Ubp3 recognition by Bre5 and into protein recognition by NTF2-like domains.
authors.affiliation: The Wistar Institute University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Keqin
authors.initials: K
authors.lastname: Li
authors.forename: Batool
authors.initials: B
authors.lastname: Ossareh-Nazari
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Catherine
authors.initials: C
authors.lastname: Dargemont
authors.forename: Ronen
authors.initials: R
authors.lastname: Marmorstein
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D003067:Coenzymes / Q000737:chemistry / Q000378:metabolism; D010450:Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D003067:Coenzymes; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; D010450:Endopeptidases; C503886:Bre5 protein, S cerevisiae; C101111:UBP3 protein, S cerevisiae