1YX6

Solution Structure of S5a UIM-2/Ubiquitin Complex

Summary for 1YX6

• Entry DOI: 10.2210/pdb1yx6/pdb
• Related: 1D3Z 1TBE 1YX4 1YX5
• NMR Information: BMRB: 6233
• Descriptor: 26S proteasome non-ATPase regulatory subunit 4, Ubiquitin (2 entities in total)
• Functional Keywords: polyubiquitin, proteasome, s5a, uim, hydrolase
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 25423.12

Authors

Wang, Q.,Young, P.,Walters, K.J. (deposition date: 2005-02-19, release date: 2005-04-19, Last modification date: 2024-05-22)

Primary citation

Wang, Q.,Young, P.,Walters, K.J.
Structure of S5a Bound to Monoubiquitin Provides a Model for Polyubiquitin Recognition
J.Mol.Biol., 348:727-739, 2005

PubMed Abstract: Ubiquitin is a key regulatory molecule in diverse cellular events. How cells determine the outcome of ubiquitylation remains unclear; however, a likely determinant is the specificity of ubiquitin receptor proteins for polyubiquitin chains of certain length and linkage. Proteasome subunit S5a contains two ubiquitin-interacting motifs (UIMs) through which it recruits ubiquitylated substrates to the proteasome for their degradation. Here, we report the structure of S5a (196-306) alone and complexed with two monoubiquitin molecules. This construct contains the two UIMs of S5a and we reveal their different ubiquitin-binding mechanisms and provide a rationale for their unique specificities for different ubiquitin-like domains. Furthermore, we provide direct evidence that S5a (196-306) binds either K63-linked or K48-linked polyubiquitin, and in both cases prefers longer chains. On the basis of these results we present a model for how S5a and other ubiquitin-binding proteins recognize polyubiquitin.

PubMed: 15826667
DOI: 10.1016/j.jmb.2005.03.007

Experimental method

SOLUTION NMR