2CKL

Ring1b-Bmi1 E3 catalytic domain structure


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure and E3-Ligase Activity of the Ring-Ring Complex of Polycomb Proteins Bmi1 and Ring1B.

Buchwald, G.Van Der Stoop, P.Weichenrieder, O.Perrakis, A.Van Lohuizen, M.Sixma, T.K.

(2006) Embo J. 25: 2465

  • DOI: 10.1038/sj.emboj.7601144

  • PubMed Abstract: 
  • Polycomb group proteins Ring1b and Bmi1 (B-cell-specific Moloney murine leukaemia virus integration site 1) are critical components of the chromatin modulating PRC1 complex. Histone H2A ubiquitination by the PRC1 complex strongly depends on the Ring1 ...

    Polycomb group proteins Ring1b and Bmi1 (B-cell-specific Moloney murine leukaemia virus integration site 1) are critical components of the chromatin modulating PRC1 complex. Histone H2A ubiquitination by the PRC1 complex strongly depends on the Ring1b protein. Here we show that the E3-ligase activity of Ring1b on histone H2A is enhanced by Bmi1 in vitro. The N-terminal Ring-domains are sufficient for this activity and Ring1a can replace Ring1b. E2 enzymes UbcH5a, b, c or UbcH6 support this activity with varying processivity and selectivity. All four E2s promote autoubiquitination of Ring1b without affecting E3-ligase activity. We solved the crystal structure of the Ring-Ring heterodimeric complex of Ring1b and Bmi1. In the structure the arrangement of the Ring-domains is similar to another H2A E3 ligase, the BRCA1/BARD1 complex, but complex formation depends on an N-terminal arm of Ring1b that embraces the Bmi1 Ring-domain. Mutation of a critical residue in the E2/E3 interface shows that catalytic activity resides in Ring1b and not in Bmi1. These data provide a foundation for understanding the critical enzymatic activity at the core of the PRC1 polycomb complex, which is implicated in stem cell maintenance and cancer.


    Organizational Affiliation

    Division of Molecular Carcinogenesis and Center for Biomedical Genetics, Netherlands Cancer Institute, Amsterdam, Netherlands.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
POLYCOMB GROUP RING FINGER PROTEIN 4
A
108Mus musculusMutation(s): 0 
Gene Names: Bmi1 (Bmi-1, Pcgf4)
Find proteins for P25916 (Mus musculus)
Go to UniProtKB:  P25916
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
UBIQUITIN LIGASE PROTEIN RING2
B
165Mus musculusMutation(s): 0 
Gene Names: Rnf2 (DinG, Ring1b)
EC: 2.3.2.27
Find proteins for Q9CQJ4 (Mus musculus)
Go to UniProtKB:  Q9CQJ4
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
IOD
Query on IOD

Download SDF File 
Download CCD File 
A, B
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.179 
  • Space Group: P 63
Unit Cell:
Length (Å)Angle (°)
a = 120.046α = 90.00
b = 120.046β = 90.00
c = 27.096γ = 120.00
Software Package:
Software NamePurpose
SHARPphasing
MOSFLMdata reduction
REFMACrefinement
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-05-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance