3TGX

IL-21:IL21R complex

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
Pharos: Disease Associations

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
B	d3tgxb_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d3tgxd_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
F	d3tgxf_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
H	d3tgxh_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
J	d3tgxj_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
L	d3tgxl_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
N	d3tgxn_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
P	d3tgxp_	All alpha proteins	4-helical cytokines	4-helical cytokines	Short-chain cytokines	Interleukin-21 (IL-21)	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
B	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
D	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
F	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
H	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
J	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
L	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
N	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	SCOP2B (2022-06-29)
P	SCOP2B Superfamily	4-helical cytokines	8035273	3001717	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	F_UNCLASSIFIED	e3tgxA2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
C	F_UNCLASSIFIED	e3tgxC1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
E	F_UNCLASSIFIED	e3tgxE1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
G	F_UNCLASSIFIED	e3tgxG1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
I	F_UNCLASSIFIED	e3tgxI1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
K	F_UNCLASSIFIED	e3tgxK1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
M	F_UNCLASSIFIED	e3tgxM1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
O	F_UNCLASSIFIED	e3tgxO1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: F_UNCLASSIFIED	ECOD (1.6)
B	PF02372	e3tgxB1	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
D	PF02372	e3tgxD2	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
F	PF02372	e3tgxF2	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
H	PF02372	e3tgxH1	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
J	PF02372	e3tgxJ2	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
L	PF02372	e3tgxL1	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
N	PF02372	e3tgxN2	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)
P	PF02372	e3tgxP2	A: alpha bundles	X: Ferritin/Heme oxygenase/4-helical cytokines	H: 4-helical cytokines (From Topology)	T: 4-helical cytokines	F: PF02372	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
C	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
E	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
G	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
I	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
K	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
M	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
O	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (4.3.0)
B	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
D	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
F	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
H	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
J	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
L	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
N	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)
P	1.20.1250.70	Mainly Alpha	Up-down Bundle	Growth Hormone	Chain: A	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B, D, F, H, J B, D, F, H, J, L, N, P	PF02372	Interleukin 15 (IL15)	Interleukin 15	Interleukin-15 (IL-15) is a cytokine that possesses a variety of biological functions, including stimulation and maintenance of cellular immune responses [1]. Structurally these proteins are short-chain 4-helical cytokines.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, C, E, G, I A, C, E, G, I, K, M, O	Interleukin-21 receptor	molecular transducer activity transmembrane signaling receptor activity signaling receptor activity cytokine receptor activity immune receptor activity interleukin-21 receptor activity	cellular response to stimulus response to organic substance regulation of biological process regulation of cellular process response to stimulus cell surface receptor signaling pathway signaling biological regulation response to cytokine cytokine-mediated signaling pathway cell communication cellular response to chemical stimulus response to chemical cellular response to cytokine stimulus cellular response to stimulus response to organic substance regulation of biological process regulation of cellular process response to stimulus cell surface receptor signaling pathway signaling biological regulation response to cytokine cytokine-mediated signaling pathway cell communication cellular response to chemical stimulus response to chemical cellular response to cytokine stimulus cellular process cellular response to organic substance signal transduction adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains lymphocyte mediated immunity immune response immune system process B cell mediated immunity leukocyte mediated immunity immunoglobulin mediated immune response adaptive immune response immune effector process multicellular organismal process cell activation natural killer cell activation lymphocyte activation leukocyte activation	cell periphery cell surface membrane plasma membrane cellular anatomical entity external side of plasma membrane side of membrane
B, D, F, H, J B, D, F, H, J, L, N, P	Interleukin-21	protein binding binding molecular function activator activity signaling receptor binding molecular function regulator activity cytokine activity signaling receptor regulator activity receptor ligand activity signaling receptor activator activity cytokine receptor binding growth factor receptor binding interleukin-2 receptor binding	regulation of immune effector process lymphocyte mediated immunity positive regulation of leukocyte mediated immunity positive regulation of response to biotic stimulus regulation of cellular process response to stimulus response to biotic stimulus positive regulation of leukocyte mediated cytotoxicity positive regulation of immune response positive regulation of natural killer cell mediated immunity leukocyte mediated immunity regulation of immune system process natural killer cell mediated immunity positive regulation of immune system process regulation of immune effector process lymphocyte mediated immunity positive regulation of leukocyte mediated immunity positive regulation of response to biotic stimulus regulation of cellular process response to stimulus response to biotic stimulus positive regulation of leukocyte mediated cytotoxicity positive regulation of immune response positive regulation of natural killer cell mediated immunity leukocyte mediated immunity regulation of immune system process natural killer cell mediated immunity positive regulation of immune system process regulation of biological process regulation of natural killer cell mediated immunity immune response response to other organism regulation of innate immune response response to external stimulus leukocyte mediated cytotoxicity immune effector process regulation of leukocyte mediated immunity regulation of response to stimulus defense response to other organism positive regulation of defense response natural killer cell mediated cytotoxicity regulation of immune response positive regulation of natural killer cell mediated cytotoxicity regulation of cell killing positive regulation of cell killing regulation of defense response regulation of response to biotic stimulus regulation of natural killer cell mediated cytotoxicity biological process involved in interspecies interaction between organisms regulation of response to external stimulus positive regulation of lymphocyte mediated immunity positive regulation of biological process positive regulation of response to stimulus positive regulation of response to external stimulus response to stress regulation of response to stress innate immune response positive regulation of immune effector process response to external biotic stimulus positive regulation of cellular process positive regulation of innate immune response defense response regulation of leukocyte mediated cytotoxicity biological regulation defense response to symbiont regulation of lymphocyte mediated immunity immune system process cellular process cell killing cellular response to stimulus cell surface receptor signaling pathway via STAT signaling peptidyl-tyrosine modification cell communication organic substance metabolic process peptidyl-amino acid modification phosphate-containing compound metabolic process protein metabolic process signal transduction protein modification process phosphorus metabolic process tyrosine phosphorylation of STAT protein organonitrogen compound metabolic process protein phosphorylation cell surface receptor signaling pathway phosphorylation cellular metabolic process primary metabolic process macromolecule modification metabolic process macromolecule metabolic process peptidyl-tyrosine phosphorylation cell surface receptor signaling pathway via JAK-STAT regulation of inflammatory response positive regulation of inflammatory response inflammatory response developmental process cellular developmental process anatomical structure maturation cell differentiation anatomical structure development cell development cell maturation developmental maturation cell population proliferation positive regulation of cell population proliferation regulation of cell population proliferation multicellular organismal process positive regulation of tissue remodeling tissue remodeling positive regulation of multicellular organismal process regulation of multicellular organismal process regulation of tissue remodeling germinal center B cell differentiation mononuclear cell differentiation mature B cell differentiation B cell activation involved in immune response lymphocyte activation cell activation involved in immune response lymphocyte differentiation leukocyte activation B cell differentiation leukocyte activation involved in immune response lymphocyte activation involved in immune response mature B cell differentiation involved in immune response hemopoiesis B cell activation cell activation leukocyte differentiation immunoglobulin production cellular biosynthetic process positive regulation of cellular metabolic process positive regulation of macromolecule biosynthetic process positive regulation of metabolic process positive regulation of biosynthetic process organic substance biosynthetic process positive regulation of macromolecule metabolic process positive regulation of immunoglobulin production regulation of biosynthetic process production of molecular mediator of immune response regulation of cellular metabolic process regulation of macromolecule metabolic process gene expression macromolecule biosynthetic process regulation of cellular biosynthetic process regulation of gene expression biosynthetic process regulation of immunoglobulin production positive regulation of gene expression positive regulation of production of molecular mediator of immune response regulation of macromolecule biosynthetic process regulation of production of molecular mediator of immune response regulation of metabolic process positive regulation of cellular biosynthetic process positive regulation of phosphorylation positive regulation of phosphate metabolic process regulation of primary metabolic process regulation of phosphate metabolic process positive regulation of protein phosphorylation positive regulation of phosphorus metabolic process regulation of protein metabolic process regulation of phosphorus metabolic process regulation of protein modification process regulation of protein phosphorylation positive regulation of protein metabolic process positive regulation of peptidyl-tyrosine phosphorylation positive regulation of protein modification process regulation of tyrosine phosphorylation of STAT protein regulation of peptidyl-tyrosine phosphorylation positive regulation of tyrosine phosphorylation of STAT protein regulation of phosphorylation cytokine production regulation of cytokine production interleukin-17 production regulation of interleukin-17 production positive regulation of interleukin-17 production positive regulation of cytokine production CD4-positive, alpha-beta T cell differentiation CD4-positive, alpha-beta T cell differentiation involved in immune response alpha-beta T cell differentiation involved in immune response alpha-beta T cell differentiation T cell activation involved in immune response alpha-beta T cell activation involved in immune response T cell activation CD4-positive, alpha-beta T cell activation alpha-beta T cell activation T follicular helper cell differentiation T cell differentiation T-helper cell differentiation T cell differentiation involved in immune response positive regulation of B cell proliferation regulation of leukocyte activation regulation of cell activation leukocyte proliferation positive regulation of lymphocyte activation positive regulation of cell activation regulation of B cell proliferation lymphocyte proliferation regulation of B cell activation positive regulation of leukocyte activation positive regulation of mononuclear cell proliferation regulation of lymphocyte proliferation regulation of leukocyte proliferation positive regulation of lymphocyte proliferation B cell proliferation positive regulation of B cell activation mononuclear cell proliferation positive regulation of leukocyte proliferation regulation of mononuclear cell proliferation regulation of lymphocyte activation positive regulation of T cell activation positive regulation of T cell proliferation regulation of leukocyte cell-cell adhesion positive regulation of leukocyte cell-cell adhesion leukocyte cell-cell adhesion positive regulation of cell-cell adhesion cell adhesion cell-cell adhesion regulation of cell-cell adhesion T cell proliferation positive regulation of cell adhesion regulation of cell adhesion regulation of T cell activation regulation of T cell proliferation defense response to virus response to virus regulation of type II interferon production type II interferon production positive regulation of type II interferon production cellular response to virus	extracellular region cellular anatomical entity extracellular space

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, C, E, G, I A, C, E, G, I, K, M, O	IPR003961	Fibronectin type III	Domain
A, C, E, G, I A, C, E, G, I, K, M, O	IPR003531	Short hematopoietin receptor, family 1, conserved site	Conserved Site
A, C, E, G, I A, C, E, G, I, K, M, O	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
A, C, E, G, I A, C, E, G, I, K, M, O	IPR036116	Fibronectin type III superfamily	Homologous Superfamily
B, D, F, H, J B, D, F, H, J, L, N, P	IPR003443	Interleukin-15/Interleukin-21 family	Family
B, D, F, H, J B, D, F, H, J, L, N, P	IPR009079	Four-helical cytokine-like, core	Homologous Superfamily

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A, C, E, G, I A, C, E, G, I, K, M, O	Pharos: Q9HBE5	cryptosporidiosis-chronic cholangitis-liver disease syndrome IgE responsiveness, atopic ulcerative colitis allergic rhinitis head and neck cancer invasive ductal breast carcinoma Lupus Erythematosus, Systemic primary biliary cholangitis systemic lupus erythematosus asthma cutaneous lupus erythematosus malignant mesothelioma psoriasis tuberculosis chronic obstructive pulmonary disease cryptosporidiosis-chronic cholangitis-liver disease syndrome IgE responsiveness, atopic ulcerative colitis allergic rhinitis head and neck cancer invasive ductal breast carcinoma Lupus Erythematosus, Systemic primary biliary cholangitis systemic lupus erythematosus asthma cutaneous lupus erythematosus malignant mesothelioma psoriasis tuberculosis chronic obstructive pulmonary disease ductal breast carcinoma in situ interstitial cystitis lung adenocarcinoma osteosarcoma Sjogren syndrome
B, D, F, H, J B, D, F, H, J, L, N, P	Pharos: Q9HBE4	celiac disease common variable immunodeficiency IL21-related infantile inflammatory bowel disease rheumatoid arthritis Acquired Hypogammaglobulinemia attention deficit hyperactivity disorder, inattentive type juvenile idiopathic arthritis primary biliary cholangitis sclerosing cholangitis alopecia areata bipolar disorder psoriasis systemic lupus erythematosus atopic eczema

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 R01GM133198.