2QQH

Structure of C8a-MACPF reveals mechanism of membrane attack in complement immune defense


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.255 
  • R-Value Observed: 0.256 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structure of C8alpha-MACPF reveals mechanism of membrane attack in complement immune defense.

Hadders, M.A.Beringer, D.X.Gros, P.

(2007) Science 317: 1552-1554

  • DOI: https://doi.org/10.1126/science.1147103
  • Primary Citation of Related Structures:  
    2QQH

  • PubMed Abstract: 

    Membrane attack is important for mammalian immune defense against invading microorganisms and infected host cells. Proteins of the complement membrane attack complex (MAC) and the protein perforin share a common MACPF domain that is responsible for membrane insertion and pore formation. We determined the crystal structure of the MACPF domain of complement component C8alpha at 2.5 angstrom resolution and show that it is structurally homologous to the bacterial, pore-forming, cholesterol-dependent cytolysins. The structure displays two regions that (in the bacterial cytolysins) refold into transmembrane beta hairpins, forming the lining of a barrel pore. Local hydrophobicity explains why C8alpha is the first complement protein to insert into the membrane. The size of the MACPF domain is consistent with known C9 pore sizes. These data imply that these mammalian and bacterial cytolytic proteins share a common mechanism of membrane insertion.


  • Organizational Affiliation

    Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Complement component C8 alpha chain334Homo sapiensMutation(s): 1 
Gene Names: C8A
UniProt & NIH Common Fund Data Resources
Find proteins for P07357 (Homo sapiens)
Explore P07357 
Go to UniProtKB:  P07357
PHAROS:  P07357
GTEx:  ENSG00000157131 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07357
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.255 
  • R-Value Observed: 0.256 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 178.92α = 90
b = 178.92β = 90
c = 75.009γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
ADSCdata collection
MOSFLMdata reduction
SCALAdata scaling
SOLVEphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-09-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-08-02
    Changes: Source and taxonomy
  • Version 1.3: 2021-10-20
    Changes: Database references, Derived calculations