In molecular biology, 2'-5'-oligoadenylate synthetase (2-5A synthetase) is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
() 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 ...
signal. It is an antiviral enzyme that counteracts
viral attack by degrading
RNA
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
s, both viral and host. The enzyme uses
ATP in 2'-specific
nucleotidyl transfer
reactions to synthesize 2'-5'-oligoadenylates, which activate
latent ribonuclease (RNase-L), 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, carboxy 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 t ...
half of 2'-5'-oligoadenylate synthetase, also referred to as
domain
A domain is a geographic area controlled by a single person or organization. Domain may also refer to:
Law and human geography
* Demesne, in English common law and other Medieval European contexts, lands directly managed by their holder rather ...
2 of the enzyme, is largely
alpha-helical and
homologous 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 19 ...
repeat. It carries the region of enzymatic activity between at the extreme C-terminal end.
Human proteins
*
OAS1
*
OAS2
*
OAS3
See also
*
OASL
References
{{InterPro content, IPR018952
Protein domains