Annotations: 1KXR

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1kxra_	Alpha and beta proteins (a+b)	Cysteine proteinases	Cysteine proteinases	Calpain large subunit, catalytic domain (domain II)	Calpain large subunit, catalytic domain (domain II)	Norway rat (Rattus norvegicus ) [TaxId: 10116 ],	SCOPe (2.08)
B	d1kxrb_	Alpha and beta proteins (a+b)	Cysteine proteinases	Cysteine proteinases	Calpain large subunit, catalytic domain (domain II)	Calpain large subunit, catalytic domain (domain II)	Norway rat (Rattus norvegicus ) [TaxId: 10116 ],	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	8036715	3001808	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Cysteine proteinases	8036715	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_C2	e1kxrA1	A: a+b complex topology	X: Cysteine proteinases-like	H: Cysteine proteinases (From Topology)	T: Cysteine proteinases	F: Peptidase_C2	ECOD (1.6)
B	Peptidase_C2	e1kxrB1	A: a+b complex topology	X: Cysteine proteinases-like	H: Cysteine proteinases (From Topology)	T: Cysteine proteinases	F: Peptidase_C2	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)
B	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, B	PF00648	Calpain family cysteine protease (Peptidase_C2)	Calpain family cysteine protease	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	thiol protease DOMAINS I AND II	cation binding ion binding binding calcium ion binding metal ion binding small molecule binding peptidase activity catalytic activity, acting on a protein hydrolase activity catalytic activity cysteine-type peptidase activity calcium-dependent cysteine-type endopeptidase activity cysteine-type endopeptidase activity endopeptidase activity cation binding ion binding binding calcium ion binding metal ion binding small molecule binding peptidase activity catalytic activity, acting on a protein hydrolase activity catalytic activity cysteine-type peptidase activity calcium-dependent cysteine-type endopeptidase activity cysteine-type endopeptidase activity endopeptidase activity cytoskeletal protein binding protein binding enzyme binding	proteolysis self proteolysis metabolic process cellular process primary metabolic process protein metabolic process macromolecule metabolic process gene expression macromolecule biosynthetic process protein maturation protein autoprocessing biosynthetic process protein processing developmental process proteolysis self proteolysis metabolic process cellular process primary metabolic process protein metabolic process macromolecule metabolic process gene expression macromolecule biosynthetic process protein maturation protein autoprocessing biosynthetic process protein processing developmental process multicellular organismal process mammary gland morphogenesis mammary gland development gland development animal organ development anatomical structure morphogenesis gland morphogenesis tissue remodeling anatomical structure development mammary gland involution animal organ morphogenesis catabolic process protein catabolic process macromolecule catabolic process response to angiotensin response to stimulus response to hormone response to chemical response to endogenous stimulus response to peptide hormone response to oxygen-containing compound response to nitrogen compound positive regulation of cardiac muscle cell apoptotic process regulation of biological process regulation of cellular process positive regulation of programmed cell death muscle cell apoptotic process positive regulation of striated muscle cell apoptotic process regulation of apoptotic process biological regulation positive regulation of biological process regulation of cardiac muscle cell apoptotic process regulation of muscle cell apoptotic process regulation of programmed cell death cell death positive regulation of apoptotic process cardiac muscle cell apoptotic process positive regulation of muscle cell apoptotic process regulation of striated muscle cell apoptotic process striated muscle cell apoptotic process apoptotic process programmed cell death positive regulation of cellular process regulation of cytoskeleton organization regulation of cellular component organization regulation of actin filament-based process regulation of cellular component size negative regulation of biological process cellular component organization cellular component biogenesis regulation of protein-containing complex assembly cellular component assembly protein-containing complex assembly actin filament-based process negative regulation of cellular process negative regulation of protein polymerization regulation of actin filament polymerization cellular component organization or biogenesis regulation of biological quality negative regulation of supramolecular fiber organization negative regulation of actin filament polymerization protein polymerization actin polymerization or depolymerization regulation of actin filament organization actin cytoskeleton organization actin filament polymerization negative regulation of cellular component organization protein-containing complex organization negative regulation of cytoskeleton organization regulation of actin polymerization or depolymerization actin filament organization regulation of cellular component biogenesis regulation of organelle organization negative regulation of protein-containing complex assembly organelle organization negative regulation of organelle organization regulation of protein polymerization regulation of actin filament length regulation of actin cytoskeleton organization regulation of supramolecular fiber organization supramolecular fiber organization cytoskeleton organization regulation of anatomical structure size cellular response to stimulus cellular response to oxidative stress cellular response to chemical stress cellular response to oxygen-containing compound cellular response to hydrogen peroxide response to reactive oxygen species response to hydrogen peroxide response to oxidative stress cellular response to reactive oxygen species cellular response to chemical stimulus cellular response to stress response to stress regulation of molecular function regulation of catalytic activity regulation of cell motility positive regulation of leukocyte cell-cell adhesion regulation of leukocyte adhesion to vascular endothelial cell leukocyte cell-cell adhesion leukocyte tethering or rolling positive regulation of cell-cell adhesion cell adhesion cell-cell adhesion positive regulation of leukocyte tethering or rolling cellular extravasation regulation of cell migration regulation of cell-cell adhesion cell migration regulation of immune system process cell motility locomotion positive regulation of cell adhesion regulation of cell adhesion regulation of leukocyte migration positive regulation of leukocyte adhesion to vascular endothelial cell leukocyte migration regulation of leukocyte tethering or rolling leukocyte adhesion to vascular endothelial cell immune system process regulation of locomotion regulation of leukocyte cell-cell adhesion regulation of cellular extravasation regulation of vascular permeability system process circulatory system process positive regulation of vascular permeability vascular process in circulatory system blood circulation signaling negative regulation of signaling negative regulation of intracellular signal transduction regulation of signal transduction regulation of non-canonical NF-kappaB signal transduction intracellular signal transduction negative regulation of cell communication cell communication regulation of intracellular signal transduction intracellular signaling cassette signal transduction negative regulation of non-canonical NF-kappaB signal transduction regulation of signaling negative regulation of response to stimulus non-canonical NF-kappaB signal transduction negative regulation of signal transduction regulation of response to stimulus regulation of cell communication protein catabolic process at postsynapse protein catabolic process at synapse response to arsenic-containing substance receptor catabolic process receptor metabolic process	membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure mitochondrion organelle cytoplasm intracellular membrane-bounded organelle cell periphery plasma membrane membrane cornified envelope cytosol presynapse membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure mitochondrion organelle cytoplasm intracellular membrane-bounded organelle cell periphery plasma membrane membrane cornified envelope cytosol presynapse synapse cell junction lytic vacuole vacuole lysosome glutamatergic synapse postsynaptic density postsynapse neuron to neuron synapse postsynaptic specialization asymmetric synapse

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR022684	Peptidase C2, calpain family	Family
A, B	IPR000169	Cysteine peptidase, cysteine active site	Active Site
A, B	IPR038765	Papain-like cysteine peptidase superfamily	Homologous Superfamily
A, B	IPR002048	EF-hand domain	Domain
A, B	IPR011992	EF-hand domain pair	Homologous Superfamily
A, B	IPR001300	Peptidase C2, calpain, catalytic domain	Domain
A, B	IPR018247	EF-Hand 1, calcium-binding site	Binding Site
A, B	IPR022683	Peptidase C2, calpain, domain III	Domain
A, B	IPR033883	Calpain subdomain III	Domain
A, B	IPR036213	Calpain large subunit, domain III superfamily	Homologous Superfamily
A, B	IPR022682	Peptidase C2, calpain, large subunit, domain III	Domain

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.