Immunoglobulin superfamily

Immunoglobulin superfamily
Antibody in complex with hen egg white lysozyme.[1]
Identifiers
Symbol	IgSF
Pfam	PF00047
Pfam clan	CL0159
InterPro	IPR013151
PROSITE	PS50835
SCOP2	1tlk / SCOPe / SUPFAM
OPM superfamily	193
OPM protein	3bib
CDD	cd00096
Membranome	2
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

The immunoglobulin superfamily (IgSF) is a large protein superfamily of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. Molecules are categorized as members of this superfamily based on shared structural features with immunoglobulins (also known as antibodies); they all possess a domain known as an immunoglobulin domain or fold. Members of the IgSF include cell surface antigen receptors, co-receptors and co-stimulatory molecules of the immune system, molecules involved in antigen presentation to lymphocytes, cell adhesion molecules, certain cytokine receptors and intracellular muscle proteins. They are commonly associated with roles in the immune system. Otherwise, the sperm-specific protein IZUMO1, a member of the immunoglobulin superfamily, has also been identified as the only sperm membrane protein essential for sperm-egg fusion.