PDBe 3e8l

X-ray diffraction
2.48Å resolution

The Crystal Structure of the Double-headed Arrowhead Protease Inhibitor A in Complex with Two Trypsins


Function and Biology Details

Structure analysis Details

Assembly composition:
hetero trimer (preferred)
Entry contents:
2 distinct polypeptide molecules
Macromolecules (2 distinct):
Serine proteinase inhibitor A Chain: C
Molecule details ›
Chain: C
Length: 185 amino acids
Theoretical weight: 20.23 KDa
Source organism: Sagittaria sagittifolia
Expression system: Escherichia coli
  • Canonical: Q7M1P4 (Residues: 26-201; Coverage: 95%)
Sequence domains: Trypsin and protease inhibitor
Structure domains: Trefoil (Acidic Fibroblast Growth Factor, subunit A)
Cationic trypsin Chains: A, B
Molecule details ›
Chains: A, B
Length: 223 amino acids
Theoretical weight: 23.32 KDa
Source organism: Bos taurus
  • Canonical: P00760 (Residues: 24-246; Coverage: 97%)
Sequence domains: Trypsin
Structure domains: Trypsin-like serine proteases

Ligands and Environments

No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: RIGAKU MICROMAX-007
Spacegroup: C2221
Unit cell:
a: 76.634Å b: 110.863Å c: 152.991Å
α: 90° β: 90° γ: 90°
R R work R free
0.197 0.194 0.245
Expression system: Escherichia coli