1R5I

Crystal structure of the MAM-MHC complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.238 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of Mycoplasma arthritidis mitogen complexed with HLA-DR1 reveals a novel superantigen fold and a dimerized superantigen-MHC complex.

Zhao, Y.Li, Z.Drozd, S.J.Guo, Y.Mourad, W.Li, H.

(2004) Structure 12: 277-288

  • DOI: 10.1016/j.str.2004.01.008

  • PubMed Abstract: 
  • Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen that can activate large fractions of T cells bearing particular TCR Vbeta elements. Here we report the crystal structure of MAM complexed with a major histocompatibility complex (MHC) ant ...

    Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen that can activate large fractions of T cells bearing particular TCR Vbeta elements. Here we report the crystal structure of MAM complexed with a major histocompatibility complex (MHC) antigen, HLA-DR1, loaded with haemagglutinin peptide 306-318 (HA). The structure reveals that MAM has a novel fold composed of two alpha-helical domains. This fold is entirely different from that of the pyrogenic superantigens, consisting of a beta-grasped motif and a beta barrel. In the complex, the N-terminal domain of MAM binds orthogonally to the MHC alpha1 domain and the bound HA peptide, and to a lesser extent to the MHC beta1 domain. Two MAM molecules form an asymmetric dimer and cross-link two MHC antigens to form a plausible, dimerized MAM-MHC complex. These data provide the first crystallographic evidence that superantigens can dimerize MHC molecules. Based on our structure, a model of the TCR2MAM2MHC2 complex is proposed.


    Organizational Affiliation

    Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DR alpha chain
A, E
181Homo sapiensGene Names: HLA-DRA (HLA-DRA1)
Find proteins for P01903 (Homo sapiens)
Go to Gene View: HLA-DRA
Go to UniProtKB:  P01903
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DRB1-1 beta chain
B, F
190Homo sapiensGene Names: HLA-DRB1
Find proteins for P04229 (Homo sapiens)
Go to Gene View: HLA-DRB1
Go to UniProtKB:  P04229
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Hemagglutinin peptide
C, G
13Influenza A virus (strain A/Swine/Hong Kong/81/1978 H3N2)Gene Names: HA
Find proteins for P11133 (Influenza A virus (strain A/Swine/Hong Kong/81/1978 H3N2))
Go to UniProtKB:  P11133
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
superantigen
D, H
216Mycoplasma arthritidisN/A
Find proteins for Q48898 (Mycoplasma arthritidis)
Go to UniProtKB:  Q48898
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
C, D, E, H
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, E
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.238 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 138.286α = 90.00
b = 178.814β = 90.00
c = 179.554γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data reduction
SOLVEphasing
CCP4data scaling
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-03-16
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance