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	protein binding binding serpin family protein binding cysteine-type peptidase activity peptidase activity catalytic activity, acting on a protein hydrolase activity catalytic activity	proteolysis metabolic process cellular process primary metabolic process protein metabolic process macromolecule metabolic process	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR038765	Papain-like cysteine peptidase superfamily	Homologous Superfamily
A	IPR025661	Cysteine peptidase, asparagine active site	Active Site
A	IPR000169	Cysteine peptidase, cysteine active site	Active Site
A	IPR025660	Cysteine peptidase, histidine 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	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.