2-5-oligoadenylate synthetase, N-terminal (IPR006116)

Short name: 2-5-oligoadenylate_synth_N

Overlapping homologous superfamilies


Domain relationships



2'-5'-oligoadenylate synthetases constitute a family of interferon-induced enzymes that bind double-stranded RNA (dsRNA) and polymerise ATP into 2'-5' linked oligomers of adenosine (pppA(2'p5'A)n) (2-5A) of various lengths. The 2-5A molecules activate a latent ribonuclease (Rnase L) that then cleaves single-stranded RNAs; as a result protein synthesis and virus growth are inhibited. Thus 2-5A synthetases play an important role in the antiviral action of interferons.

Three distinct classes of 2-5A synthetases have been described that correspond to proteins of 40-46 Kd, 69-71 Kd, and 100 Kd. The 40 and 46 Kd forms are produced by alternative splicing of the same gene. The 69 and 71 Kd forms are also produced by alternative splicing of a gene and consist of two adjacent homologous domains whose sequences are highly similar to that of the 40/46 Kd forms. The sequence of the 100 Kd form is not yet known.

This domain spans a region rich in glycine residues which has been proposed [PMID: 1577824] to be part of the ATP-binding site. The C-terminal domain is described in IPR006117.

GO terms

Biological Process

GO:0006955 immune response

Molecular Function

GO:0005524 ATP binding
GO:0003723 RNA binding
GO:0016740 transferase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles