X-ray diffraction
2.6Å resolution

Crystal Structure of Human Complement C3b in complex with Smallpox Inhibitor of Complement (SPICE)


Function and Biology Details

Structure analysis Details

Assembly composition:
hetero trimer (preferred)
Entry contents:
3 distinct polypeptide molecules
Macromolecules (5 distinct):
Complement C3 beta chain Chain: A
Molecule details ›
Chain: A
Length: 645 amino acids
Theoretical weight: 71.39 KDa
Source organism: Homo sapiens
  • Canonical: P01024 (Residues: 23-667; Coverage: 39%)
Gene names: C3, CPAMD1
Sequence domains:
Structure domains:
Complement C3b alpha' chain Chain: B

Ligands and Environments

Carbohydrate polymer : NEW Components: NAG, BMA, FUC
Carbohydrate polymer : NEW Components: NAG
No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: ESRF BEAMLINE ID14-4
Spacegroup: P1
Unit cell:
a: 68.891Å b: 83.311Å c: 127.377Å
α: 75.03° β: 76.2° γ: 68.5°
R R work R free
0.199 0.198 0.23
Expression system: Escherichia coli