1BUN

STRUCTURE OF BETA2-BUNGAROTOXIN: POTASSIUM CHANNEL BINDING BY KUNITZ MODULES AND TARGETED PHOSPHOLIPASE ACTION

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Membrane Protein Annotation: OPM

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1buna_	All alpha proteins	Phospholipase A2, PLA2	Phospholipase A2, PLA2	Vertebrate phospholipase A2	Snake phospholipase A2	(Bungarus multicinctus ) [TaxId: 8616 ],	SCOPe (2.08)
B	d1bunb_	Small proteins	BPTI-like	BPTI-like	Small Kunitz-type inhibitors & BPTI-like toxins	beta2-bungarotoxin, neurotoxin chain	(Bungarus multicinctus ) [TaxId: 8616 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	Vertebrate phospholipase A2	8026682	4001493	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Phospholipase A2, PLA2	8039061	3001690	SCOP2 (2022-06-29)
B	SCOP2 Family	Small Kunitz-type inhibitors & BPTI-like toxins	8026174	4003337	SCOP2 (2022-06-29)
B	SCOP2 Superfamily	BPTI-like	8038553	3000628	SCOP2 (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	Phospholip_A2_1	e1bunA1	A: few secondary structure elements	X: Phospholipase A2, PLA2 (From Topology)	H: Phospholipase A2, PLA2 (From Topology)	T: Phospholipase A2, PLA2	F: Phospholip_A2_1	ECOD (1.6)
B	Kunitz_BPTI	e1bunB1	A: few secondary structure elements	X: BPTI-like (From Topology)	H: BPTI-like (From Topology)	T: BPTI-like	F: Kunitz_BPTI	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.20.90.10	Mainly Alpha	Up-down Bundle	Phospholipase A2	Phospholipase A2 domain	CATH (4.3.0)
B	4.10.410.10	Few Secondary Structures	Irregular	Factor Xa Inhibitor	Pancreatic trypsin inhibitor Kunitz domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00068	Phospholipase A2 (Phospholip_A2_1)	Phospholipase A2	Phospholipase A2 releases fatty acids from the second carbon group of glycerol. Perhaps the best known members are secreted snake venoms, but also found in secreted pancreatic and membrane-associated forms. Structure is all-alpha, with two core disul ...	Phospholipase A2 releases fatty acids from the second carbon group of glycerol. Perhaps the best known members are secreted snake venoms, but also found in secreted pancreatic and membrane-associated forms. Structure is all-alpha, with two core disulfide-linked helices and a calcium-binding loop. This alignment represents the major family of PLA2s. A second minor family, defined by the honeybee venom PLA2 PDB:1POC and related sequences from Gila monsters (Heloderma), is not recognised. This minor family conserves the core helix pair but is substantially different elsewhere. The PROSITE pattern PA2_HIS, specific to the first core helix, recognises both families.	Domain
B	PF00014	Kunitz/Bovine pancreatic trypsin inhibitor domain (Kunitz_BPTI)	Kunitz/Bovine pancreatic trypsin inhibitor domain	Indicative of a protease inhibitor, usually a serine protease inhibitor. Structure is a disulfide rich alpha+beta fold. BPTI (bovine pancreatic trypsin inhibitor) is an extensively studied model structure. Certain family members are similar to the ...	Indicative of a protease inhibitor, usually a serine protease inhibitor. Structure is a disulfide rich alpha+beta fold. BPTI (bovine pancreatic trypsin inhibitor) is an extensively studied model structure. Certain family members are similar to the tick anticoagulant peptide (TAP, Swiss:P17726). This is a highly selective inhibitor of factor Xa in the blood coagulation pathways [1]. TAP molecules are highly dipolar [2], and are arranged to form a twisted two- stranded antiparallel beta-sheet followed by an alpha helix [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	BETA2-BUNGAROTOXIN	cation binding ion binding binding calcium ion binding metal ion binding small molecule binding phospholipase A2 activity calcium-dependent phospholipase A2 activity hydrolase activity, acting on ester bonds hydrolase activity catalytic activity phospholipase activity lipase activity calcium-independent phospholipase A2 activity cation binding ion binding binding calcium ion binding metal ion binding small molecule binding phospholipase A2 activity calcium-dependent phospholipase A2 activity hydrolase activity, acting on ester bonds hydrolase activity catalytic activity phospholipase activity lipase activity calcium-independent phospholipase A2 activity toxin activity phospholipid binding lipid binding	organic anion transport carboxylic acid transport secretion transport arachidonate transport lipid localization lipid transport establishment of localization organic acid transport localization arachidonate secretion monocarboxylic acid transport fatty acid transport icosanoid transport macromolecule localization organic anion transport carboxylic acid transport secretion transport arachidonate transport lipid localization lipid transport establishment of localization organic acid transport localization arachidonate secretion monocarboxylic acid transport fatty acid transport icosanoid transport macromolecule localization icosanoid secretion long-chain fatty acid transport lipid catabolic process catabolic process metabolic process cellular process primary metabolic process lipid metabolic process phospholipid metabolic process organophosphate metabolic process phosphate-containing compound metabolic process phosphorus metabolic process	cellular anatomical structure extracellular region
B	BETA2-BUNGAROTOXIN	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 potassium channel regulator activity channel regulator activity ion channel regulator activity transporter regulator activity toxin activity	-	cellular anatomical structure extracellular region extracellular space

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR033112	Phospholipase A2, aspartic acid active site	Active Site
A	IPR033113	Phospholipase A2, histidine active site	Active Site
A	IPR001211	Phospholipase A2	Family
A	IPR036444	Phospholipase A2 domain superfamily	Homologous Superfamily
A	IPR016090	Phospholipase A2 domain	Domain
B	IPR002223	Pancreatic trypsin inhibitor Kunitz domain	Domain
B	IPR050098	Tissue factor pathway inhibitor/Kunitz-type serine protease inhibitor-like	Family
B	IPR020901	Proteinase inhibitor I2, Kunitz, conserved site	Conserved Site
B	IPR036880	Pancreatic trypsin inhibitor Kunitz domain superfamily	Homologous Superfamily

Membrane Protein Annotation: OPM OPM Database Homepage

Chains	External Link	Type	Class	Superfamily	Family
A, B	OPM	Monotopic/peripheral	All alpha monotopic/peripheral	Secretory phospholipase A2	Vertebrate secretory phospholipase A2

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.