1IM3

Crystal Structure of the human cytomegalovirus protein US2 bound to the MHC class I molecule HLA-A2/tax


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Antigen presentation subverted: Structure of the human cytomegalovirus protein US2 bound to the class I molecule HLA-A2.

Gewurz, B.E.Gaudet, R.Tortorella, D.Wang, E.W.Ploegh, H.L.Wiley, D.C.

(2001) Proc.Natl.Acad.Sci.USA 98: 6794-6799

  • DOI: 10.1073/pnas.121172898

  • PubMed Abstract: 
  • Many persistent viruses have evolved the ability to subvert MHC class I antigen presentation. Indeed, human cytomegalovirus (HCMV) encodes at least four proteins that down-regulate cell-surface expression of class I. The HCMV unique short (US)2 glyco ...

    Many persistent viruses have evolved the ability to subvert MHC class I antigen presentation. Indeed, human cytomegalovirus (HCMV) encodes at least four proteins that down-regulate cell-surface expression of class I. The HCMV unique short (US)2 glycoprotein binds newly synthesized class I molecules within the endoplasmic reticulum (ER) and subsequently targets them for proteasomal degradation. We report the crystal structure of US2 bound to the HLA-A2/Tax peptide complex. US2 associates with HLA-A2 at the junction of the peptide-binding region and the alpha3 domain, a novel binding surface on class I that allows US2 to bind independently of peptide sequence. Mutation of class I heavy chains confirms the importance of this binding site in vivo. Available data on class I-ER chaperone interactions indicate that chaperones would not impede US2 binding. Unexpectedly, the US2 ER-luminal domain forms an Ig-like fold. A US2 structure-based sequence alignment reveals that seven HCMV proteins, at least three of which function in immune evasion, share the same fold as US2. The structure allows design of further experiments to determine how US2 targets class I molecules for degradation.


    Related Citations: 
    • Sec61-mediated transfer of a membrane protein from the endoplasmic reticulum to the proteasome for destruction
      Wiertz, E.J.,Tortorella, D.,Bogyo, M.,Rapoport, T.A.,Ploegh, H.L.
      (1996) Nature 384: 432
    • Human cytomegalovirus US2 endoplasmic reticulum-lumenal domain dictates association with major histocompatibility complex class I in a locus-specific manner
      Gewurz, B.E.,Wang, E.W.,Tortorella, D.,Schust, D.S.,Ploegh, H.L.
      (2001) J.Virol. 75: 5197
    • The structure and stability of an HLA-A*0201/octameric tax peptide complex with an empty conserved peptide-N-terminal binding site
      Khan, A.R.,Baker, B.M.,Ghosh, B.,E Biddison, W.,Wiley, D.C.
      (2000) J.Immunol. 164: 6398


    Organizational Affiliation

    Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA CLASS I HISTOCOMPATIBILITY ANTIGEN, A-2 ALPHA CHAIN
A, E, I, M
275Homo sapiensMutation(s): 0 
Gene Names: HLA-A (HLAA)
Find proteins for P01892 (Homo sapiens)
Go to Gene View: HLA-A
Go to UniProtKB:  P01892
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
beta-2-microglobulin
B, F, J, N
100Homo sapiensMutation(s): 0 
Gene Names: B2M
Find proteins for P61769 (Homo sapiens)
Go to Gene View: B2M
Go to UniProtKB:  P61769
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Human T-cell lymphotropic virus type 1 Tax peptide
C, G, K, O
9Human T-cell leukemia virus 1Mutation(s): 0 
Gene Names: tax
Find proteins for P14079 (Human T-cell leukemia virus 1)
Go to UniProtKB:  P14079
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
cytomegalovirus protein US2
D, H, L, P
95Human cytomegalovirus (strain AD169)Mutation(s): 0 
Gene Names: US2
Find proteins for P09713 (Human cytomegalovirus (strain AD169))
Go to UniProtKB:  P09713
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.206 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 95.480α = 109.02
b = 96.700β = 109.46
c = 99.540γ = 107.93
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
CNSphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-06-06
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance