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 substrates, and the enzyme converts the substrates into different molecules known as products. A ...
() 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 the ...
signal. It is an antiviral enzyme that counteracts
viral 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 in 2'-specific
nucleotidyl
Nucleotidyltransferases are transferase enzymes of phosphorus-containing groups, e.g., substituents of nucleotidylic acids or simply nucleoside monophosphates. The general reaction of transferring a nucleoside monophosphate moiety from A to B, can ...
transfer
reactions
Reaction may refer to a process or to a response to an action, event, or exposure:
Physics and chemistry
*Chemical reaction
*Nuclear reaction
*Reaction (physics), as defined by Newton's third law
*Chain reaction (disambiguation).
Biology and me ...
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 e ...
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 1980s. Fo ...
repeat. 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
2'-5'-oligoadenylate synthetase 2 is an enzyme that in humans is encoded by the ''OAS2'' gene.
This gene encodes a member of the 2-5A synthetase family, essential proteins involved in the innate immune response to viral infection. The encoded pr ...
*
OAS3
2'-5'-oligoadenylate synthetase 3 is an enzyme that in humans is encoded by the ''OAS3'' gene.
This gene encodes an enzyme included in the 2', 5' oligoadenylate synthase family. This enzyme is induced by interferons and catalyzes the 2', 5' o ...
See also
*
OASL
References
{{InterPro content, IPR018952
Protein domains