2NYK

Crystal structure of m157 from mouse cytomegalovirus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.214 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural elucidation of the m157 mouse cytomegalovirus ligand for Ly49 natural killer cell receptors.

Adams, E.J.Juo, Z.S.Venook, R.T.Boulanger, M.J.Arase, H.Lanier, L.L.Garcia, K.C.

(2007) Proc.Natl.Acad.Sci.Usa 104: 10128-10133

  • DOI: 10.1073/pnas.0703735104

  • PubMed Abstract: 
  • Natural killer (NK) cells express activating and inhibitory receptors that, in concert, survey cells for proper expression of cell surface major histocompatibility complex (MHC) class I molecules. The mouse cytomegalovirus encodes an MHC-like protein ...

    Natural killer (NK) cells express activating and inhibitory receptors that, in concert, survey cells for proper expression of cell surface major histocompatibility complex (MHC) class I molecules. The mouse cytomegalovirus encodes an MHC-like protein, m157, which is the only known viral antigen to date capable of engaging both activating (Ly49H) and inhibitory (Ly49I) NK cell receptors. We have determined the 3D structure of m157 and studied its biochemical and cellular interactions with the Ly49H and Ly49I receptors. m157 has a characteristic MHC-fold, yet possesses several unique structural features not found in other MHC class I-like molecules. m157 does not bind peptides or other small ligands, nor does it associate with beta(2)-microglobulin. Instead, m157 engages in extensive intra- and intermolecular interactions within and between its domains to generate a compact minimal MHC-like molecule. m157's binding affinity for Ly49I (K(d) approximately 0.2 microM) is significantly higher than that of classical inhibitory Ly49-MHC interactions. Analysis of viral escape mutations on m157 that render it resistant to NK killing reveals that it is likely to be recognized by Ly49H in a binding mode that differs from Ly49/MHC-I. In addition, Ly49H+ NK cells can efficiently lyse RMA cells expressing m157, despite the presence of native MHC class I. Collectively, our results show that m157 represents a structurally divergent form of MHC class I-like proteins that directly engage Ly49 receptors with appreciable affinity in a noncanonical fashion.


    Organizational Affiliation

    Departments of Molecular and Cellular Physiology and Structural Biology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
M157
A
285Murid herpesvirus 1Mutation(s): 1 
Gene Names: m157
Find proteins for Q6XK79 (Murid herpesvirus 1)
Go to UniProtKB:  Q6XK79
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FUC
Query on FUC

Download SDF File 
Download CCD File 
A
ALPHA-L-FUCOSE
C6 H12 O5
SHZGCJCMOBCMKK-SXUWKVJYSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.214 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 120.028α = 90.00
b = 43.805β = 101.52
c = 62.321γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
REFMACrefinement
CNSrefinement
SHARPphasing
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2006-11-20 
  • Released Date: 2007-05-29 
  • Deposition Author(s): Garcia, K.C.

Revision History 

  • Version 1.0: 2007-05-29
    Type: Initial release
  • Version 1.1: 2007-10-17
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance