Annotations: 9PAP

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d9papa_	Alpha and beta proteins (a+b)	Cysteine proteinases	Cysteine proteinases	Papain-like	Papain	papaya (Carica papaya ) [TaxId: 3649 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Cysteine proteinases	8036216	3001808	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	Peptidase_C1	e9papA1	A: a+b complex topology	X: Cysteine proteinases-like	H: Cysteine proteinases (From Topology)	T: Cysteine proteinases	F: Peptidase_C1	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.90.70.10	Alpha Beta	Alpha-Beta Complex	Cathepsin B	Chain A	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00112	Papain family cysteine protease (Peptidase_C1)	Papain family cysteine protease	-	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	PAPAIN	cysteine-type peptidase activity peptidase activity catalytic activity, acting on a protein cysteine-type endopeptidase activity hydrolase activity catalytic activity endopeptidase activity protein binding binding serpin family protein binding	catabolic process proteolysis involved in protein catabolic process proteolysis metabolic process primary metabolic process protein catabolic process protein metabolic process macromolecule metabolic process macromolecule catabolic process	extracellular region extracellular space cellular anatomical entity membrane-bounded organelle intracellular organelle intracellular anatomical structure organelle lytic vacuole vacuole cytoplasm intracellular membrane-bounded organelle lysosome

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR025661	Cysteine peptidase, asparagine active site	Active Site
A	IPR000169	Cysteine peptidase, cysteine active site	Active Site
A	IPR013128	Peptidase C1A	Family
A	IPR000668	Peptidase C1A, papain C-terminal	Domain
A	IPR013201	Cathepsin propeptide inhibitor domain (I29)	Domain
A	IPR038765	Papain-like cysteine peptidase superfamily	Homologous Superfamily
A	IPR025660	Cysteine peptidase, histidine active site	Active Site
A	IPR039417	Papain-like cysteine endopeptidase	Domain

Protein Modification Annotation

Modified Residue(s)
Chain	Residue(s)	Description
A	OCS	Parent Component: CYS RESID: AA0556 PSI-MOD : L-cysteic acid (L-cysteine sulfonic acid) MOD:00460

Structure Motif Annotation: Mechanism and Catalytic Site Atlas M-CSA Database Homepage

Chains	Enzyme Name	Description	Catalytic Residues
A	papain M-CSA #174	Papin is a member of the thiol protease family, which is a large, well-studied group with a well-known \"catalytic triad\" motif in which a cysteine acts as the catalytic nucleophile, activated by His and Asn. Papin catalyses the hydrolysis of proteins with broad specificity for peptide bonds, but shows a marked preference for an amino acid bearing a large hydrophobic side chain at the P2 position and does not accept Val in P1'.	Defined by 4 residues: GLN:A-19CYS:A-25HIS:A-159ASN:A-175 \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif EC: 3.4.22.2 (PDB Primary Data) Search M-CSA Motif + EC 3.4.22.2

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.