DB code: S00448

RLCP classification 1.13.30000.44 : Hydrolysis
CATH domain : Cathepsin B; Chain A Catalytic domain
CSA 8pch
M-CSA 8pch

CATH domain Related DB codes (homologues) : Cathepsin B; Chain A S00444 S00445 S00447 S00449 S00450 S00451 S00446 S00518

Uniprot Enzyme Name
UniprotKB Protein name Synonyms Contains RefSeq MEROPS Pfam
O46427 Cathepsin H
Cathepsin H mini chain
Cathepsin H heavy chain
Cathepsin H light chain
NP_999094.1 (Protein)
NM_213929.2 (DNA/RNA sequence)
C01.040 (Cysteine)
PF08246 (Inhibitor_I29)
PF00112 (Peptidase_C1)
[Graphical View]

KEGG enzyme name
cathepsin H
cathepsin B3
benzoylarginine-naphthylamide (BANA) hydrolase (obsolete)
cathepsin Ba, aleurain
N-benzoylarginine-beta-naphthylamide hydrolase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
O46427 CATH_PIG Hydrolysis of proteins, acting as an aminopeptidase (notably, cleaving Arg-|-Xaa bonds) as well as an endopeptidase. Composed of cathepsin H and mini chain, disulfide-linked. Cathepsin H may be split into heavy and light chain. All chains are held together by disulfide bonds. Lysosome.

KEGG Pathways
Map code Pathways E.C.

Compound table
Substrates Products Intermediates
KEGG-id C00017 C00012 C00001 C00017 C00012
Compound Protein Peptide H2O Protein Peptide
Type peptide/protein peptide/protein H2O peptide/protein peptide/protein
ChEBI 15377
PubChem 22247451
8pchA Unbound Unbound Unbound Unbound
1nb3A Unbound Unbound Unbound Unbound
1nb3B Unbound Unbound Unbound Unbound
1nb3C Unbound Unbound Unbound Unbound
1nb3D Unbound Unbound Unbound Unbound
1nb5A Unbound Unbound Unbound Unbound
1nb5B Unbound Unbound Unbound Unbound
1nb5C Unbound Unbound Unbound Unbound
1nb5D Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot;O46427 & literature [1]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
8pchA GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb3A GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb3B GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb3C GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb3D GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb5A GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb5B GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb5C GLN 19;CYS 25;ASN 158;HIS 159;ASN 175
1nb5D GLN 19;CYS 25;ASN 158;HIS 159;ASN 175

References for Catalytic Mechanism
References Sections No. of steps in catalysis
p.52-54, p.55-57

Comments X-ray crystallography (2.1 Angstroms)
Medline ID
PubMed ID 9493267
Journal Structure
Year 1998
Volume 6
Pages 51-61
Authors Guncar G, Podobnik M, Pungercar J, Strukelj B, Turk V, Turk D
Title Crystal structure of porcine cathepsin H determined at 2.1 A resolution: location of the mini-chain C-terminal carboxyl group defines cathepsin H aminopeptidase function.
Related PDB 8pch
Related UniProtKB O46427
Medline ID
PubMed ID 12581647
Journal J Mol Biol
Year 2003
Volume 326
Pages 875-85
Authors Jenko S, Dolenc I, Guncar G, Dobersek A, Podobnik M, Turk D
Title Crystal structure of Stefin A in complex with cathepsin H: N-terminal residues of inhibitors can adapt to the active sites of endo- and exopeptidases.
Related PDB 1nb3 1nb5
Related UniProtKB

This enzyme belongs to the peptidase family-C1.
Although this enzyme has got a set of active-site residues (Gln19, Cys25, His159 & Asn175), as observed in other homologous enzymes, such as cathepsin B, their relative positions are slightly different from those of other homologous enzymes (see [1]). Firstly, the position of His159 is slightly distant from the catalytic Cys25, and does not form a thiolate-imidazolium ion pair with the residue. Secondly, His159 interacts with Asn158, instead of the conserved Asn175. This ovserved structure might be an inactive form of the enzyme.

Created Updated
2002-07-04 2009-02-26