Molecular basis for bre5 cofactor recognition by the ubp3 deubiquitylating enzyme.
Li, K., Ossareh-Nazari, B., Liu, X., Dargemont, C., Marmorstein, R.(2007) J Mol Biol 372: 194-204
- PubMed: 17632125 
- DOI: https://doi.org/10.1016/j.jmb.2007.06.052
- Primary Citation of Related Structures:  
2QIY - PubMed 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.
Organizational Affiliation: 
The Wistar Institute University of Pennsylvania, Philadelphia, PA 19104, USA.