Annotations: 8K4Q

Crystal structure of nanobody HuNb103 bound to human interleukin-4 receptor subunit alpha

External Resource: Annotation

Domain Annotation: ECOD Classification
SAbDab Antibody Annotation
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
D	DUF520	e8k4qD1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: DUF520	ECOD (v295.2)
B	Rhodanese	e8k4qB01	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: Rhodanese	ECOD (v295.2)
C	DUF520	e8k4qC1	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: DUF520	ECOD (v295.2)
A	Rhodanese	e8k4qA01	A: alpha arrays	X: Hypothetical protein YqbG-like	H: Hypothetical protein YqbG-like	T: alpha/beta-Hydrolases	F: Rhodanese	ECOD (v295.2)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B, D	Heavy Chain	IGHV3	-	interleukin-4 receptor subunit alpha	SAbDab (2026-10-16)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, C	PF09238	Interleukin-4 receptor alpha chain, N-terminal (IL4Ra_N)	Interleukin-4 receptor alpha chain, N-terminal	Members of this family are related in overall topology to fibronectin type III modules and fold into a sandwich comprising seven antiparallel beta sheets arranged in a three-strand and a four-strand beta-pleated sheet. They are required for binding o ...	Members of this family are related in overall topology to fibronectin type III modules and fold into a sandwich comprising seven antiparallel beta sheets arranged in a three-strand and a four-strand beta-pleated sheet. They are required for binding of interleukin-4 to the receptor alpha chain, which is a crucial event for the generation of a Th2-dominated early immune response [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
B, D	IL-4R nanobody HuNb103	-	-	-
A, C	Interleukin-4 receptor subunit alpha	molecular transducer activity transmembrane signaling receptor activity signaling receptor activity cytokine receptor activity immune receptor activity	production of molecular mediator involved in inflammatory response multicellular organismal process response to stimulus defense response response to stress inflammatory response	cellular anatomical structure membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, C	IPR003531	Short hematopoietin receptor, family 1, conserved site	Conserved Site
A, C	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
A, C	IPR003961	Fibronectin type III	Domain
A, C	IPR015319	Interleukin-4 receptor alpha, N-terminal	Domain
A, C	IPR036116	Fibronectin type III superfamily	Homologous Superfamily