PDBe 3h7d

X-ray diffraction
2.24Å resolution

The crystal structure of the cathepsin K Variant M5 in complex with chondroitin-4-sulfate


Function and Biology Details

Reaction catalysed:
Broad proteolytic activity. With small-molecule substrates and inhibitors, the major determinant of specificity is P2, which is preferably Leu, Met > Phe, and not Arg. 
Biochemical function:
Biological process:
Cellular component:
  • not assigned

Structure analysis Details

Assemblies composition:
monomeric (preferred)
homo dimer
Entry contents:
1 distinct polypeptide molecule
Cathepsin K Chains: A, E
Molecule details ›
Chains: A, E
Length: 215 amino acids
Theoretical weight: 23.46 KDa
Source organism: Homo sapiens
Expression system: Escherichia coli
  • Canonical: P43235 (Residues: 115-329; Coverage: 69%)
Gene names: CTSK, CTSO, CTSO2
Sequence domains: Papain family cysteine protease
Structure domains: Cysteine proteinases

Ligands and Environments

No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: ALS BEAMLINE 8.3.1
Spacegroup: C2
Unit cell:
a: 140.564Å b: 42.014Å c: 87.509Å
α: 90° β: 94.19° γ: 90°
R R work R free
0.18 0.177 0.238
Expression system: Escherichia coli