2A73

Human Complement Component C3


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.30 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.233 

wwPDB Validation   3D Report Full Report



Literature

Structures of complement component C3 provide insights into the function and evolution of immunity.

Janssen, B.J.Huizinga, E.G.Raaijmakers, H.C.Roos, A.Daha, M.R.Nilsson-Ekdahl, K.Nilsson, B.Gros, P.

(2005) Nature 437: 505-511

  • DOI: 10.1038/nature04005
  • Primary Citation of Related Structures:  
    2A74, 2A73

  • PubMed Abstract: 
  • The mammalian complement system is a phylogenetically ancient cascade system that has a major role in innate and adaptive immunity. Activation of component C3 (1,641 residues) is central to the three complement pathways and results in inflammation and el ...

    The mammalian complement system is a phylogenetically ancient cascade system that has a major role in innate and adaptive immunity. Activation of component C3 (1,641 residues) is central to the three complement pathways and results in inflammation and elimination of self and non-self targets. Here we present crystal structures of native C3 and its final major proteolytic fragment C3c. The structures reveal thirteen domains, nine of which were unpredicted, and suggest that the proteins of the alpha2-macroglobulin family evolved from a core of eight homologous domains. A double mechanism prevents hydrolysis of the thioester group, essential for covalent attachment of activated C3 to target surfaces. Marked conformational changes in the alpha-chain, including movement of a critical interaction site through a ring formed by the domains of the beta-chain, indicate an unprecedented, conformation-dependent mechanism of activation, regulation and biological function of C3.


    Organizational Affiliation

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



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Complement C3 A643Homo sapiensMutation(s): 0 
Gene Names: C3CPAMD1
Find proteins for P01024 (Homo sapiens)
Explore P01024 
Go to UniProtKB:  P01024
NIH Common Fund Data Resources
PHAROS:  P01024
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Complement C3 B991Homo sapiensMutation(s): 0 
Gene Names: C3CPAMD1
Find proteins for P01024 (Homo sapiens)
Explore P01024 
Go to UniProtKB:  P01024
NIH Common Fund Data Resources
PHAROS:  P01024
Protein Feature View
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 3
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
C
2 N-Glycosylation Oligosaccharides Interaction
Entity ID: 4
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
D
5 N-Glycosylation Oligosaccharides Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.30 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.233 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.98α = 90
b = 156.26β = 90
c = 271.2γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-09-27
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary