Annotations: 1C9P

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B	d1c9pb_	Small proteins	Knottins (small inhibitors, toxins, lectins)	Leech antihemostatic proteins	Huristasin-like	Bdellastasin	medicinal leech (Hirudo medicinalis ) [TaxId: 6421 ],	SCOPe (2.08)
A	d1c9pa_	All beta proteins	Trypsin-like serine proteases	Trypsin-like serine proteases	Eukaryotic proteases	Trypsin(ogen)	(Sus scrofa ) [TaxId: 9823 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
B	SCOP2B Superfamily	Leech antihemostatic proteins	8032718	3000489	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Trypsin-like serine proteases	8036522	3000114	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)
B	Antistasin	e1c9pB1	A: few secondary structure elements	X: Huristasin-like (From Topology)	H: Huristasin-like (From Topology)	T: Huristasin-like	F: Antistasin	ECOD (1.6)
A	Trypsin_1	e1c9pA1	A: beta barrels	X: cradle loop barrel	H: RIFT-related	T: FMN-binding split barrel 2	F: Trypsin_1	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B	2.10.22.10	Mainly Beta	Ribbon	Antistasin	domain 1	CATH (4.3.0)
A	2.40.10.10	Mainly Beta	Beta Barrel	Thrombin, subunit H	Trypsin-like serine proteases	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B	PF02822	Antistasin family (Antistasin)	Antistasin family	Members of this family are inhibitors of trypsin family proteases. This domain is highly disulphide bonded. The domain is also found in some large extracellular proteins in multiple copies.	Domain
A	PF00089	Trypsin (Trypsin)	Trypsin	-	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
B	BDELLASTASIN	enzyme regulator activity molecular function inhibitor activity peptidase regulator activity serine-type endopeptidase inhibitor activity molecular function regulator activity enzyme inhibitor activity peptidase inhibitor activity endopeptidase regulator activity endopeptidase inhibitor activity	-	extracellular region cellular anatomical entity
A	TRYPSIN	peptidase activity catalytic activity, acting on a protein serine hydrolase activity serine-type peptidase activity hydrolase activity serine-type endopeptidase activity catalytic activity endopeptidase activity cation binding ion binding binding metal ion binding small molecule binding	organic substance metabolic process organonitrogen compound metabolic process proteolysis metabolic process primary metabolic process protein metabolic process macromolecule metabolic process multicellular organismal process digestion	extracellular region extracellular space cellular anatomical entity

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
B	IPR004094	Antistasin-like domain	Domain
B	IPR011061	Hirudin/antistatin	Homologous Superfamily
A	IPR001254	Serine proteases, trypsin domain	Domain
A	IPR009003	Peptidase S1, PA clan	Homologous Superfamily
A	IPR043504	Peptidase S1, PA clan, chymotrypsin-like fold	Homologous Superfamily
A	IPR018114	Serine proteases, trypsin family, histidine active site	Active Site
A	IPR001314	Peptidase S1A, chymotrypsin family	Family
A	IPR033116	Serine proteases, trypsin family, serine active site	Active Site

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.