The 2- 5- oligoadenylate synthetase (OAS) family is comprised of four members: OAS1, OAS2, OAS3 and OASL. These proteins are induced by interferons and function to convert ATP into 2- 5- linked oligomers of adenosine in the presence of double-stranded RNA and magnesium ions. Copper, iron and zinc ions strongly inhibit the OAS enzymatic activity, while manganese ions can replace magnesium ions as an activator. The OAS family plays a significant role in the inhibition of cellular protein synthesis, apoptosis and growth, and its members are important factors in viral infection resistance. OAS3, also referred to as p100, contains three adjacent OAS1-like domains and maps to the human chromosome 12q24.2
