6NXK

Ubiquitin binding variants

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.223 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history. 


Literature

Protein engineering of a ubiquitin-variant inhibitor of APC/C identifies a cryptic K48 ubiquitin chain binding site.

Watson, E.R., Grace, C.R.R., Zhang, W., Miller, D.J., Davidson, I.F., Prabu, J.R., Yu, S., Bolhuis, D.L., Kulko, E.T., Vollrath, R., Haselbach, D., Stark, H., Peters, J.M., Brown, N.G., Sidhu, S.S., Schulman, B.A.

(2019) Proc Natl Acad Sci U S A 116: 17280-17289

  • DOI: 10.1073/pnas.1902889116
  • Primary Citation of Related Structures:  
    6NXK, 6NXL, 6OB1

  • PubMed Abstract: 

    • Ubiquitin (Ub)-mediated proteolysis is a fundamental mechanism used by eukaryotic cells to maintain homeostasis and protein quality, and to control timing in biological processes. Two essential aspects of Ub regulation are conjugation through E1-E2-E3 enzymatic cascades and recognition by Ub-binding domains ...

    Ubiquitin (Ub)-mediated proteolysis is a fundamental mechanism used by eukaryotic cells to maintain homeostasis and protein quality, and to control timing in biological processes. Two essential aspects of Ub regulation are conjugation through E1-E2-E3 enzymatic cascades and recognition by Ub-binding domains. An emerging theme in the Ub field is that these 2 properties are often amalgamated in conjugation enzymes. In addition to covalent thioester linkage to Ub's C terminus for Ub transfer reactions, conjugation enzymes often bind noncovalently and weakly to Ub at "exosites." However, identification of such sites is typically empirical and particularly challenging in large molecular machines. Here, studying the 1.2-MDa E3 ligase anaphase-promoting complex/cyclosome (APC/C), which controls cell division and many aspects of neurobiology, we discover a method for identifying unexpected Ub-binding sites. Using a panel of Ub variants (UbVs), we identify a protein-based inhibitor that blocks Ub ligation to APC/C substrates in vitro and ex vivo. Biochemistry, NMR, and cryo-electron microscopy (cryo-EM) structurally define the UbV interaction, explain its inhibitory activity through binding the surface on the APC2 subunit that recruits the E2 enzyme UBE2C, and ultimately reveal that this APC2 surface is also a Ub-binding exosite with preference for K48-linked chains. The results provide a tool for probing APC/C activity, have implications for the coordination of K48-linked Ub chain binding by APC/C with the multistep process of substrate polyubiquitylation, and demonstrate the power of UbV technology for identifying cryptic Ub-binding sites within large multiprotein complexes.

    Organizational Affiliation: 

    Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Polyubiquitin-CA, B76Homo sapiensMutation(s): 0 
Gene Names: UBC
UniProt & NIH Common Fund Data Resources
Find proteins for P0CG48 (Homo sapiens)
Explore P0CG48 
Go to UniProtKB:  P0CG48
PHAROS:  P0CG48
Protein Feature View
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  • Reference Sequence
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Anaphase-promoting complex subunit 2C, D90Homo sapiensMutation(s): 0 
Gene Names: ANAPC2, APC2, KIAA1406
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UJX6 (Homo sapiens)
Explore Q9UJX6 
Go to UniProtKB:  Q9UJX6
PHAROS:  Q9UJX6
GTEx:  ENSG00000176248
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.223 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.893α = 90
b = 63.368β = 90
c = 100.135γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2020-01-15
    Type: Initial release
  • Version 1.1: 2021-02-03
    Changes: Database references