PDBe 3cbj

X-ray diffraction
1.8Å resolution

Chagasin-Cathepsin B complex


Function and Biology Details

Reaction catalysed:
Hydrolysis of proteins with broad specificity for peptide bonds. Preferentially cleaves -Arg-Arg-|- bonds in small molecule substrates (thus differing from cathepsin L). In addition to being an endopeptidase, shows peptidyl-dipeptidase activity, liberating C-terminal dipeptides.
Biochemical function:
Biological process:
Cellular component:

Structure analysis Details

Assemblies composition:
hetero dimer (preferred)
hetero tetramer
Entry contents:
2 distinct polypeptide molecules
Macromolecules (2 distinct):
Chagasin Chain: B
Molecule details ›
Chain: B
Length: 110 amino acids
Theoretical weight: 12.05 KDa
Source organism: Trypanosoma cruzi
Expression system: Escherichia coli
  • Canonical: Q966X9 (Residues: 1-110; Coverage: 100%)
Gene name: cha
Sequence domains: Chagasin family peptidase inhibitor I42
Structure domains: Immunoglobulin-like
Cathepsin B Chain: A
Molecule details ›
Chain: A
Length: 266 amino acids
Theoretical weight: 29.31 KDa
Source organism: Homo sapiens
Expression system: Komagataella pastoris
  • Canonical: P07858 (Residues: 74-339; Coverage: 83%)
Gene names: CPSB, CTSB
Sequence domains: Papain family cysteine protease
Structure domains: Cysteine proteinases

Ligands and Environments

1 bound ligand:

No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: MAX II BEAMLINE I911-5
Spacegroup: C2
Unit cell:
a: 135.255Å b: 30.778Å c: 79.745Å
α: 90° β: 92.68° γ: 90°
R R work R free
0.165 0.163 0.21
Expression systems:
  • Escherichia coli
  • Komagataella pastoris