Immunoglobulin Superfamily, Member 21 (IGSF21)

Immunoglobulin Superfamily, Member 21 (IGSF21) Contains 2 Ig-like (immunoglobulin-like) domains. The Fibronectin type III domain is an evolutionary conserved protein domain that is widely found in animal proteins. The fibronectin protein in which this domain was first identified contains 16 copies of this domain.

The domain is about 100 amino acids long and possesses a beta sandwich structure. Fibronectin domains are found in a wide variety of extracellular proteins. They are widely distributed in animal species, but also found more sporadically in yeast, plant and bacterial proteins. The immunoglobulin superfamily is a large group of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells.