Annotations: 8J6F

Cryo-EM structure of the Tocilizumab Fab/IL-6R complex

External Resource: Annotation

Domain Annotation: ECOD Classification
SAbDab Antibody Annotation
Thera-SAbDab Antibody Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Pharos: Disease Associations

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A [auth H]	Frizzled	e8j6fH01	A: alpha arrays	X: HTH	H: HTH	T: Three-helical HTH	F: Frizzled	ECOD (v295)
B [auth L]	Frizzled	e8j6fL01	A: alpha arrays	X: HTH	H: HTH	T: Three-helical HTH	F: Frizzled	ECOD (v295)
C [auth I]	V-set	e8j6fI1	A: alpha arrays	X: HTH	H: HTH	T: Three-helical HTH	F: V-set	ECOD (v295)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
A [auth H]	Heavy Chain	IGHV4	-	interleukin-6 receptor subunit alpha \| il6r-d2 peptide	SAbDab (2026-06-26)
B [auth L]	Light Chain	IGKV1	Kappa	interleukin-6 receptor subunit alpha \| il6r-d2 peptide	SAbDab (2026-06-26)

Thera-SAbDab Antibody Annotation Thera-SAbDab Database Homepage

Chain	Name	Target	Provenance Source
A [auth H]	Tocilizumab	IL6R/CD126	Therapeutic SAbDab (2026-06-26)
B [auth L]	Tocilizumab	IL6R/CD126	Therapeutic SAbDab (2026-06-26)

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A [auth H]	Heavy chain of Tocilizumab Fab	-	-	-
B [auth L]	Light chain of Tocilizumab Fab	-	-	-
C [auth I]	Interleukin-6 receptor subunit alpha	interleukin-11 receptor activity molecular transducer activity transmembrane signaling receptor activity signaling receptor activity cytokine receptor activity immune receptor activity ciliary neurotrophic factor binding protein binding binding cytokine binding interleukin-6 receptor activity interleukin-6 binding growth factor binding interleukin-11 binding interleukin-11 receptor activity molecular transducer activity transmembrane signaling receptor activity signaling receptor activity cytokine receptor activity immune receptor activity ciliary neurotrophic factor binding protein binding binding cytokine binding interleukin-6 receptor activity interleukin-6 binding growth factor binding interleukin-11 binding identical protein binding protein homodimerization activity protein dimerization activity enzyme binding	cellular response to stimulus regulation of biological process regulation of cellular process cell surface receptor signaling pathway response to stimulus signaling biological regulation response to cytokine cytokine-mediated signaling pathway cell communication response to peptide response to chemical cellular process cellular response to cytokine stimulus cellular response to stimulus regulation of biological process regulation of cellular process cell surface receptor signaling pathway response to stimulus signaling biological regulation response to cytokine cytokine-mediated signaling pathway cell communication response to peptide response to chemical cellular process cellular response to cytokine stimulus signal transduction regulation of biosynthetic process negative regulation of collagen metabolic process negative regulation of metabolic process negative regulation of biological process collagen biosynthetic process regulation of collagen biosynthetic process regulation of collagen metabolic process negative regulation of collagen biosynthetic process biosynthetic process negative regulation of biosynthetic process negative regulation of cellular process metabolic process collagen metabolic process regulation of metabolic process cell surface receptor signaling pathway via STAT cell death extrinsic apoptotic signaling pathway apoptotic signaling pathway apoptotic process programmed cell death cell-cell signaling autocrine signaling cell surface receptor signaling pathway via JAK-STAT multicellular organismal process positive regulation of biological process positive regulation of macromolecule biosynthetic process positive regulation of metabolic process positive regulation of biosynthetic process regulation of cytokine production cytokine production regulation of multicellular organismal process positive regulation of macromolecule metabolic process positive regulation of cellular process regulation of macromolecule metabolic process gene expression macromolecule biosynthetic process regulation of chemokine production regulation of gene expression positive regulation of gene expression chemokine production positive regulation of chemokine production positive regulation of multicellular organismal process regulation of macromolecule biosynthetic process macromolecule metabolic process positive regulation of cytokine production acute-phase response defense response response to stress inflammatory response acute inflammatory response immune response immune system process hepatic immune response organ or tissue specific immune response cell population proliferation regulation of smooth muscle cell proliferation positive regulation of cell population proliferation smooth muscle cell proliferation positive regulation of smooth muscle cell proliferation regulation of cell population proliferation muscle cell proliferation biological process involved in interspecies interaction between organisms response to other organism response to external stimulus defense response to Gram-negative bacterium response to biotic stimulus defense response to bacterium response to bacterium response to external biotic stimulus negative regulation of interleukin-8 production negative regulation of macromolecule metabolic process negative regulation of cytokine production interleukin-8 production negative regulation of gene expression negative regulation of macromolecule biosynthetic process negative regulation of multicellular organismal process regulation of interleukin-8 production positive regulation of locomotion regulation of cell motility regulation of response to external stimulus positive regulation of chemotaxis positive regulation of cell migration positive regulation of response to stimulus positive regulation of response to external stimulus taxis positive regulation of cell motility regulation of cell migration cell migration regulation of immune system process cell motility positive regulation of immune system process locomotion cell chemotaxis chemotaxis regulation of leukocyte chemotaxis regulation of leukocyte migration positive regulation of leukocyte chemotaxis positive regulation of leukocyte migration regulation of chemotaxis leukocyte migration cellular response to chemical stimulus regulation of response to stimulus regulation of locomotion leukocyte chemotaxis vascular endothelial growth factor production neutrophil mediated immunity leukocyte mediated immunity myeloid leukocyte mediated immunity immune effector process connective tissue development renal system development kidney vasculature development multicellular organism development renal system vasculature development positive regulation of glomerular mesangial cell proliferation regulation of glomerular mesangial cell proliferation anatomical structure development nephron development system development blood vessel development positive regulation of cell proliferation involved in kidney development developmental process animal organ development cell proliferation involved in kidney development glomerular mesangium development tissue development vasculature development circulatory system development glomerulus development glomerular mesangial cell proliferation glomerulus vasculature development kidney development animal gross anatomical part developmental process interleukin-6 production positive regulation of interleukin-6 production regulation of interleukin-6 production paracrine signaling ciliary neurotrophic factor-mediated signaling pathway pancreas development endocrine system development endocrine pancreas development interleukin-6-mediated signaling pathway response to interleukin-6 cellular response to interleukin-6 positive regulation of cell communication positive regulation of signal transduction regulation of signal transduction intracellular signal transduction regulation of intracellular signal transduction intracellular signaling cassette regulation of signaling positive regulation of MAPK cascade positive regulation of intracellular signal transduction regulation of MAPK cascade MAPK cascade regulation of cell communication positive regulation of signaling monocyte chemotaxis mononuclear cell migration myeloid leukocyte migration regulation of osteoblast differentiation cellular developmental process regulation of developmental process regulation of cell differentiation osteoblast differentiation positive regulation of developmental process positive regulation of osteoblast differentiation ossification positive regulation of cell differentiation cell differentiation defense response to Gram-positive bacterium CD4-positive or CD8-positive, alpha-beta T cell lineage commitment adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains cell development mononuclear cell differentiation lymphocyte activation lymphocyte differentiation cell activation involved in immune response CD4-positive, alpha-beta T cell differentiation leukocyte activation 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 leukocyte activation involved in immune response alpha-beta T cell activation T cell differentiation CD4-positive, alpha-beta T cell lineage commitment lymphocyte activation involved in immune response T-helper cell differentiation alpha-beta T cell lineage commitment hemopoiesis cell activation T-helper cell lineage commitment T cell differentiation involved in immune response T cell lineage commitment adaptive immune response T-helper 17 cell lineage commitment positive T cell selection T cell selection T-helper 17 cell differentiation cell fate commitment leukocyte differentiation T-helper 17 type immune response	cell periphery cellular anatomical structure cell surface membrane plasma membrane external side of plasma membrane side of membrane protein-containing complex plasma membrane protein complex plasma membrane signaling receptor complex ciliary neurotrophic factor receptor complex membrane protein complex signaling receptor complex interleukin-6 receptor complex cell periphery cellular anatomical structure cell surface membrane plasma membrane external side of plasma membrane side of membrane protein-containing complex plasma membrane protein complex plasma membrane signaling receptor complex ciliary neurotrophic factor receptor complex membrane protein complex signaling receptor complex interleukin-6 receptor complex apical part of cell plasma membrane region apical plasma membrane extracellular region
D [auth B]	IL6R-D2 peptide	interleukin-11 receptor activity molecular transducer activity transmembrane signaling receptor activity signaling receptor activity cytokine receptor activity immune receptor activity ciliary neurotrophic factor binding protein binding binding cytokine binding interleukin-6 receptor activity interleukin-6 binding growth factor binding interleukin-11 binding interleukin-11 receptor activity molecular transducer activity transmembrane signaling receptor activity signaling receptor activity cytokine receptor activity immune receptor activity ciliary neurotrophic factor binding protein binding binding cytokine binding interleukin-6 receptor activity interleukin-6 binding growth factor binding interleukin-11 binding identical protein binding protein homodimerization activity protein dimerization activity enzyme binding	cellular response to stimulus regulation of biological process regulation of cellular process cell surface receptor signaling pathway response to stimulus signaling biological regulation response to cytokine cytokine-mediated signaling pathway cell communication response to peptide response to chemical cellular process cellular response to cytokine stimulus cellular response to stimulus regulation of biological process regulation of cellular process cell surface receptor signaling pathway response to stimulus signaling biological regulation response to cytokine cytokine-mediated signaling pathway cell communication response to peptide response to chemical cellular process cellular response to cytokine stimulus signal transduction regulation of biosynthetic process negative regulation of collagen metabolic process negative regulation of metabolic process negative regulation of biological process collagen biosynthetic process regulation of collagen biosynthetic process regulation of collagen metabolic process negative regulation of collagen biosynthetic process biosynthetic process negative regulation of biosynthetic process negative regulation of cellular process metabolic process collagen metabolic process regulation of metabolic process cell surface receptor signaling pathway via STAT cell death extrinsic apoptotic signaling pathway apoptotic signaling pathway apoptotic process programmed cell death cell-cell signaling autocrine signaling cell surface receptor signaling pathway via JAK-STAT multicellular organismal process positive regulation of biological process positive regulation of macromolecule biosynthetic process positive regulation of metabolic process positive regulation of biosynthetic process regulation of cytokine production cytokine production regulation of multicellular organismal process positive regulation of macromolecule metabolic process positive regulation of cellular process regulation of macromolecule metabolic process gene expression macromolecule biosynthetic process regulation of chemokine production regulation of gene expression positive regulation of gene expression chemokine production positive regulation of chemokine production positive regulation of multicellular organismal process regulation of macromolecule biosynthetic process macromolecule metabolic process positive regulation of cytokine production acute-phase response defense response response to stress inflammatory response acute inflammatory response immune response immune system process hepatic immune response organ or tissue specific immune response cell population proliferation regulation of smooth muscle cell proliferation positive regulation of cell population proliferation smooth muscle cell proliferation positive regulation of smooth muscle cell proliferation regulation of cell population proliferation muscle cell proliferation biological process involved in interspecies interaction between organisms response to other organism response to external stimulus defense response to Gram-negative bacterium response to biotic stimulus defense response to bacterium response to bacterium response to external biotic stimulus negative regulation of interleukin-8 production negative regulation of macromolecule metabolic process negative regulation of cytokine production interleukin-8 production negative regulation of gene expression negative regulation of macromolecule biosynthetic process negative regulation of multicellular organismal process regulation of interleukin-8 production positive regulation of locomotion regulation of cell motility regulation of response to external stimulus positive regulation of chemotaxis positive regulation of cell migration positive regulation of response to stimulus positive regulation of response to external stimulus taxis positive regulation of cell motility regulation of cell migration cell migration regulation of immune system process cell motility positive regulation of immune system process locomotion cell chemotaxis chemotaxis regulation of leukocyte chemotaxis regulation of leukocyte migration positive regulation of leukocyte chemotaxis positive regulation of leukocyte migration regulation of chemotaxis leukocyte migration cellular response to chemical stimulus regulation of response to stimulus regulation of locomotion leukocyte chemotaxis vascular endothelial growth factor production neutrophil mediated immunity leukocyte mediated immunity myeloid leukocyte mediated immunity immune effector process connective tissue development renal system development kidney vasculature development multicellular organism development renal system vasculature development positive regulation of glomerular mesangial cell proliferation regulation of glomerular mesangial cell proliferation anatomical structure development nephron development system development blood vessel development positive regulation of cell proliferation involved in kidney development developmental process animal organ development cell proliferation involved in kidney development glomerular mesangium development tissue development vasculature development circulatory system development glomerulus development glomerular mesangial cell proliferation glomerulus vasculature development kidney development animal gross anatomical part developmental process interleukin-6 production positive regulation of interleukin-6 production regulation of interleukin-6 production paracrine signaling ciliary neurotrophic factor-mediated signaling pathway pancreas development endocrine system development endocrine pancreas development interleukin-6-mediated signaling pathway response to interleukin-6 cellular response to interleukin-6 positive regulation of cell communication positive regulation of signal transduction regulation of signal transduction intracellular signal transduction regulation of intracellular signal transduction intracellular signaling cassette regulation of signaling positive regulation of MAPK cascade positive regulation of intracellular signal transduction regulation of MAPK cascade MAPK cascade regulation of cell communication positive regulation of signaling monocyte chemotaxis mononuclear cell migration myeloid leukocyte migration regulation of osteoblast differentiation cellular developmental process regulation of developmental process regulation of cell differentiation osteoblast differentiation positive regulation of developmental process positive regulation of osteoblast differentiation ossification positive regulation of cell differentiation cell differentiation defense response to Gram-positive bacterium CD4-positive or CD8-positive, alpha-beta T cell lineage commitment adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains cell development mononuclear cell differentiation lymphocyte activation lymphocyte differentiation cell activation involved in immune response CD4-positive, alpha-beta T cell differentiation leukocyte activation 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 leukocyte activation involved in immune response alpha-beta T cell activation T cell differentiation CD4-positive, alpha-beta T cell lineage commitment lymphocyte activation involved in immune response T-helper cell differentiation alpha-beta T cell lineage commitment hemopoiesis cell activation T-helper cell lineage commitment T cell differentiation involved in immune response T cell lineage commitment adaptive immune response T-helper 17 cell lineage commitment positive T cell selection T cell selection T-helper 17 cell differentiation cell fate commitment leukocyte differentiation T-helper 17 type immune response	cell periphery cellular anatomical structure cell surface membrane plasma membrane external side of plasma membrane side of membrane protein-containing complex plasma membrane protein complex plasma membrane signaling receptor complex ciliary neurotrophic factor receptor complex membrane protein complex signaling receptor complex interleukin-6 receptor complex cell periphery cellular anatomical structure cell surface membrane plasma membrane external side of plasma membrane side of membrane protein-containing complex plasma membrane protein complex plasma membrane signaling receptor complex ciliary neurotrophic factor receptor complex membrane protein complex signaling receptor complex interleukin-6 receptor complex apical part of cell plasma membrane region apical plasma membrane extracellular region

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth I]	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
C [auth I]	IPR003530	Long hematopoietin receptor, soluble alpha chain, conserved site	Conserved Site
C [auth I]	IPR003599	Immunoglobulin domain subtype	Domain
C [auth I]	IPR013151	Immunoglobulin-like beta-sandwich domain	Domain
C [auth I]	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
C [auth I]	IPR007110	Immunoglobulin-like domain	Domain
C [auth I]	IPR003598	Immunoglobulin subtype 2	Domain
C [auth I]	IPR015321	Type I cytokine receptor, cytokine-binding domain	Domain
C [auth I]	IPR003961	Fibronectin type III	Domain
C [auth I]	IPR036116	Fibronectin type III superfamily	Homologous Superfamily
D [auth B]	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
D [auth B]	IPR003530	Long hematopoietin receptor, soluble alpha chain, conserved site	Conserved Site
D [auth B]	IPR003599	Immunoglobulin domain subtype	Domain
D [auth B]	IPR013151	Immunoglobulin-like beta-sandwich domain	Domain
D [auth B]	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
D [auth B]	IPR007110	Immunoglobulin-like domain	Domain
D [auth B]	IPR003598	Immunoglobulin subtype 2	Domain
D [auth B]	IPR015321	Type I cytokine receptor, cytokine-binding domain	Domain
D [auth B]	IPR003961	Fibronectin type III	Domain
D [auth B]	IPR036116	Fibronectin type III superfamily	Homologous Superfamily

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
C [auth I]	: P08887	rheumatoid arthritis non-small cell lung carcinoma renal cell carcinoma juvenile idiopathic arthritis chromophobe renal cell carcinoma schizophrenia osteoporosis ankylosing spondylitis papillary renal cell carcinoma collecting duct carcinoma sarcomatoid renal cell carcinoma Still's disease lung carcinoma tuberculosis myocardial infarction rheumatoid arthritis non-small cell lung carcinoma renal cell carcinoma juvenile idiopathic arthritis chromophobe renal cell carcinoma schizophrenia osteoporosis ankylosing spondylitis papillary renal cell carcinoma collecting duct carcinoma sarcomatoid renal cell carcinoma Still's disease lung carcinoma tuberculosis myocardial infarction abdominal aortic aneurysm atopic eczema breast cancer pancreatic ductal adenocarcinoma Pick disease gastric cancer hereditary diffuse gastric adenocarcinoma large cell medulloblastoma subependymal giant cell astrocytoma malignant colon neoplasm ulcerative colitis medulloblastoma myopathy allergic rhinitis atrial fibrillation osteosarcoma carpal tunnel syndrome pancreatic intraductal papillary-mucinous neoplasm with low grade dysplasia clear cell renal carcinoma pilocytic astrocytoma gastric neoplasm invasive ductal breast carcinoma Sjogren syndrome lung cancer temporal arteritis malignant mesothelioma neuromyelitis optica atypical teratoid rhabdoid tumor ovarian cancer Castleman disease pituitary cancer depressive disorder renal carcinoma glioblastoma
D [auth B]	: P08887	rheumatoid arthritis non-small cell lung carcinoma renal cell carcinoma juvenile idiopathic arthritis chromophobe renal cell carcinoma schizophrenia osteoporosis ankylosing spondylitis papillary renal cell carcinoma collecting duct carcinoma sarcomatoid renal cell carcinoma Still's disease lung carcinoma tuberculosis myocardial infarction rheumatoid arthritis non-small cell lung carcinoma renal cell carcinoma juvenile idiopathic arthritis chromophobe renal cell carcinoma schizophrenia osteoporosis ankylosing spondylitis papillary renal cell carcinoma collecting duct carcinoma sarcomatoid renal cell carcinoma Still's disease lung carcinoma tuberculosis myocardial infarction abdominal aortic aneurysm atopic eczema breast cancer pancreatic ductal adenocarcinoma Pick disease gastric cancer hereditary diffuse gastric adenocarcinoma large cell medulloblastoma subependymal giant cell astrocytoma malignant colon neoplasm ulcerative colitis medulloblastoma myopathy allergic rhinitis atrial fibrillation osteosarcoma carpal tunnel syndrome pancreatic intraductal papillary-mucinous neoplasm with low grade dysplasia clear cell renal carcinoma pilocytic astrocytoma gastric neoplasm invasive ductal breast carcinoma Sjogren syndrome lung cancer temporal arteritis malignant mesothelioma neuromyelitis optica atypical teratoid rhabdoid tumor ovarian cancer Castleman disease pituitary cancer depressive disorder renal carcinoma glioblastoma