3KMT

Crystal structure of vSET/SAH/H3 ternary complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.210 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Dimerization of a viral SET protein endows its function.

Wei, H.Zhou, M.M.

(2010) Proc Natl Acad Sci U S A 107: 18433-18438

  • DOI: 10.1073/pnas.1009911107
  • Primary Citation of Related Structures:  
    3KMT, 3KMJ, 3KMA

  • PubMed Abstract: 
  • Histone modifications are regarded as the most indispensible phenomena in epigenetics. Of these modifications, lysine methylation is of the greatest complexity and importance as site- and state-specific lysine methylation exerts a plethora of effects ...

    Histone modifications are regarded as the most indispensible phenomena in epigenetics. Of these modifications, lysine methylation is of the greatest complexity and importance as site- and state-specific lysine methylation exerts a plethora of effects on chromatin structure and gene transcription. Notably, paramecium bursaria chlorella viruses encode a conserved SET domain methyltransferase, termed vSET, that functions to suppress host transcription by methylating histone H3 at lysine 27 (H3K27), a mark for eukaryotic gene silencing. Unlike mammalian lysine methyltransferases (KMTs), vSET functions only as a dimer, but the underlying mechanism has remained elusive. In this study, we demonstrate that dimeric vSET operates with negative cooperativity between the two active sites and engages in H3K27 methylation one site at a time. New atomic structures of vSET in the free form and a ternary complex with S-adenosyl homocysteine and a histone H3 peptide and biochemical analyses reveal the molecular origin for the negative cooperativity and explain the substrate specificity of H3K27 methyltransferases. Our study suggests a "walking" mechanism, by which vSET acts all by itself to globally methylate host H3K27, which is accomplished by the mammalian EZH2 KMT only in the context of the Polycomb repressive complex.


    Organizational Affiliation

    Department of Structural and Chemical Biology, Mount Sinai School of Medicine, 1425 Madison Avenue, Box 1677, New York, NY 10029, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
A612L proteinABC119Paramecium bursaria Chlorella virus 1Mutation(s): 0 
Gene Names: A612L
Find proteins for O41094 (Paramecium bursaria Chlorella virus 1)
Explore O41094 
Go to UniProtKB:  O41094
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Histone H3GHI8Homo sapiensMutation(s): 0 
Gene Names: 
Find proteins for P68431 (Homo sapiens)
Explore P68431 
Go to UniProtKB:  P68431
NIH Common Fund Data Resources
PHAROS  P68431
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAH
Query on SAH

Download CCD File 
A, B, C
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MLZ
Query on MLZ
G,H,IL-PEPTIDE LINKINGC7 H16 N2 O2LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.210 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 155.085α = 90
b = 38.722β = 107.8
c = 73.208γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
MOLREPphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2009-11-11 
  • Released Date: 2010-11-10 
  • Deposition Author(s): Wei, H., Zhou, M.M.

Revision History 

  • Version 1.0: 2010-11-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance