Annotations: 5B5K

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	IZUMO1 N-terminal domain-like	8050778	4007041	SCOP2 (2022-06-29)
A	SCOP2 Family	IZUMO1 domain-like	8046009	4004819	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	IZUMO1 N-terminal domain-like	8092640	3002613	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Immunoglobulin (Ig) domain-like	8092639	3000071	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	PF16706	e5b5kA2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: PF16706	ECOD (1.6)
A	PF15005	e5b5kA1	A: alpha bundles	X: N-cbl like	H: Izumo sperm-egg fusion protein 1 N-terminal domain (From Topology)	T: Izumo sperm-egg fusion protein 1 N-terminal domain	F: PF15005	ECOD (1.6)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF16706	Izumo-like Immunoglobulin domain (Izumo-Ig)	Izumo-like Immunoglobulin domain	Izumo-Ig is the immunoglobulin domain on Izumo proteins from higher eukaryotes. Izumo is a typical type I membrane glycoprotein with one immunoglobulin-like domain and a putative N-glycoside link motif - glycosylation site. The full-length protein, e ...	Izumo-Ig is the immunoglobulin domain on Izumo proteins from higher eukaryotes. Izumo is a typical type I membrane glycoprotein with one immunoglobulin-like domain and a putative N-glycoside link motif - glycosylation site. The full-length protein, eg Swiss:Q8IYV9, is a molecule with a single immunoglobulin (Ig) domain. It is thought that Izumo proteins bind to putative Izumo receptors on the oocyte. Izumo is not detectable on the surface of fresh sperm but becomes exposed only after an exocytotic process, the acrosome reaction, has occurred. Studies have shown that knock-out mice (Izumo-/- males) were sterile despite normal mating behaviour and ejaculation, indicating the importance of the protein in fertilisation [1]. There is a conserved GCL sequence motif. Izumo expression has been found to be testis-specific [1,2].	Domain
A	PF15005	Izumo sperm-egg fusion, Ig domain-associated (IZUMO)	Izumo sperm-egg fusion, Ig domain-associated	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Izumo sperm-egg fusion protein 1	protein binding binding signaling receptor binding identical protein binding protein homodimerization activity protein dimerization activity cell adhesion molecule binding cell adhesion mediator activity cell-cell adhesion mediator activity protein binding involved in heterotypic cell-cell adhesion	membrane organization sexual reproduction membrane fusion reproductive process plasma membrane fusion fertilization multicellular organismal reproductive process cellular process involved in reproduction in multicellular organism cellular component organization fusion of sperm to egg plasma membrane involved in single fertilization plasma membrane organization cellular process cellular component organization or biogenesis endomembrane system organization membrane organization sexual reproduction membrane fusion reproductive process plasma membrane fusion fertilization multicellular organismal reproductive process cellular process involved in reproduction in multicellular organism cellular component organization fusion of sperm to egg plasma membrane involved in single fertilization plasma membrane organization cellular process cellular component organization or biogenesis endomembrane system organization single fertilization sperm-egg recognition cell-cell recognition cell recognition cell adhesion heterotypic cell-cell adhesion cell-cell adhesion	membrane cellular anatomical entity protein complex involved in cell-cell adhesion protein-containing complex protein complex involved in cell adhesion cell periphery plasma membrane membrane-bounded organelle acrosomal vesicle intracellular anatomical structure intracellular vesicle acrosomal membrane intracellular membrane-bounded organelle endomembrane system membrane cellular anatomical entity protein complex involved in cell-cell adhesion protein-containing complex protein complex involved in cell adhesion cell periphery plasma membrane membrane-bounded organelle acrosomal vesicle intracellular anatomical structure intracellular vesicle acrosomal membrane intracellular membrane-bounded organelle endomembrane system intracellular organelle cytoplasmic vesicle membrane bounding membrane of organelle vesicle membrane cytoplasmic vesicle organelle secretory granule secretory vesicle cytoplasm vesicle organelle membrane secretory granule membrane organelle subcompartment endoplasmic reticulum subcompartment nuclear outer membrane-endoplasmic reticulum membrane network endoplasmic reticulum endoplasmic reticulum membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR029389	Izumo sperm-egg fusion protein	Family
A	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
A	IPR032699	Izumo protein, immunoglobulin domain	Domain
A	IPR032700	Izumo sperm-egg fusion protein 1	Family

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.