Protein Domain : Type-2 ice-structuring protein IPR002353

Type	Family
Description	Marine teleosts from polar oceans can be protected from freezing in icy sea-water by serum antifreeze proteins (AFPs) or glycoproteins (AFGPs) [].These function by binding to, and preventing the growth of, ice crystals within the fish. Despite functional similarity, the proteins arestructurally diverse and include glycosylated and at least 3 non-glycosylated forms: the AFGP of nototheniids and cod are polymers of a tripeptide repeat, Ala-Ala-Thr, with a disaccharide attached to thethreonine residue; type I AFPs are Ala-rich, α-helical peptides found in flounder and sculpin; type II AFPs of sea-raven, smelt andherring are Cys-rich proteins; and type III AFPs, found in Eel pouts, are rich in β-structure. Although no direct structural information is available for type II AFPs,their sequences are similar to the carbohydrate recognition domain (CRD) of Ca2+-dependent lectins. This domain is present in a superfamily of proteins that bind sugars specifically through contact with a calciumion. The extent of similarity within the superfamily is confined to short motifs and single amino acids at intervals throughout the protein.
Short Name	AntifreezeII