In molecular biology, 2'-5'-oligoadenylate synthetase (2-5A synthetase) is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

() that reacts to

interferon Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten t ...

signal. It is an antiviral enzyme that counteracts

viral Viral means "relating to viruses" (small infectious agents). Viral may also refer to: Viral behavior, or virality Memetic behavior likened that of a virus, for example: * Viral marketing, the use of existing social networks to spread a marke ...

attack by degrading

RNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...

s, both viral and host. The enzyme uses

ATP ATP may refer to: Companies and organizations * Association of Tennis Professionals, men's professional tennis governing body * American Technical Publishers, employee-owned publishing company * ', a Danish pension * Armenia Tree Project, non ...

in 2'-specific nucleotidyl transfer reactions to synthesize 2'-5'-oligoadenylates, which activate latent ribonuclease (RNASEL), resulting in degradation of viral RNA and inhibition of virus replication. The

C-terminal The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...

half of 2'-5'-oligoadenylate synthetase, also referred to as

domain Domain may refer to: Mathematics *Domain of a function, the set of input values for which the (total) function is defined ** Domain of definition of a partial function **Natural domain of a partial function **Domain of holomorphy of a function *Do ...

2 of the enzyme, is largely

alpha-helical The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earli ...

and

homologous Homology may refer to: Sciences Biology *Homology (biology), any characteristic of biological organisms that is derived from a common ancestor *Sequence homology, biological homology between DNA, RNA, or protein sequences * Homologous chrom ...

to a tandem

ubiquitin Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. F ...

repeat Repeat may refer to: * Rerun, a rebroadcast of an episode of a radio or television program * Repeated sequence (DNA), a pattern of nucleic acid (DNA or RNA) that occurs in multiple copies throughout the genome ** CRISPR * The smallest rectangle ...

. It carries the region of enzymatic activity between at the extreme C-terminal end.

Human proteins

OAS1 2'-5'-oligoadenylate synthetase 1 is an enzyme that in humans is encoded by the ''OAS1'' gene. This gene encodes a member of the 2-5A synthetase family, which include essential proteins involved in the innate immune response to viral infection. ...

* OAS2 * OAS3

References

{{InterPro content, IPR018952 Protein domains

Human proteins

See also

References