2I6S

Complement component C2a


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.212 

wwPDB Validation   3D Report Full Report



Literature

Structure of complement component c2a: implications for convertase formation and substrate binding.

Milder, F.J.Raaijmakers, H.C.Vandeputte, M.D.Schouten, A.Huizinga, E.G.Romijn, R.A.Hemrika, W.Roos, A.Daha, M.R.Gros, P.

(2006) Structure 14: 1587-1597

  • DOI: 10.1016/j.str.2006.08.008
  • Primary Citation of Related Structures:  
    2I6S, 2I6Q

  • PubMed Abstract: 
  • C2a provides the catalytic center to the convertase complexes of the classical and lectin-binding pathways of complement activation. We determined two crystal structures of full-length C2a, with and without a pseudo ligand bound. Both structures reve ...

    C2a provides the catalytic center to the convertase complexes of the classical and lectin-binding pathways of complement activation. We determined two crystal structures of full-length C2a, with and without a pseudo ligand bound. Both structures reveal a near-active conformation of the catalytic center of the serine protease domains, while the von Willebrand factor A-type domains display an intermediate activation state of helix alpha7 with an open, activated metal-ion-dependent adhesion site. The open adhesion site likely serves to enhance the affinity for the ligand C4b, similar to "inside-out" signaling in integrins. Surprisingly, the N-terminal residues of C2a are buried in a crevice near helix alpha7, indicative of a structural switch between C2 and C2a. Extended loops on the protease domain possibly envelop the protruding anaphylatoxin domain of the substrate C3. Together with a putative substrate-induced completion of the oxyanion hole, this may contribute to the high substrate specificity of the convertases.


    Organizational Affiliation

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



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Complement C2a fragmentA517Homo sapiensMutation(s): 0 
Gene Names: C2aC2
EC: 3.4.21.43
Find proteins for P06681 (Homo sapiens)
Explore P06681 
Go to UniProtKB:  P06681
NIH Common Fund Data Resources
PHAROS  P06681
Protein Feature View
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose
B
4 N-Glycosylation Oligosaccharides Interaction
Entity ID: 3
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
C
3 N-Glycosylation Oligosaccharides Interaction
Entity ID: 4
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
D
2 N-Glycosylation Oligosaccharides Interaction
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download CCD File 
A
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.212 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.16α = 90
b = 75.08β = 110.32
c = 71.56γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
DNAdata collection
MOSFLMdata reduction
CCP4data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-10-17
    Type: Initial release
  • Version 1.1: 2008-05-01
    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, Database references, Derived calculations, Structure summary