Viperin (Virus Inhibitory Protein, Endoplasmic Reticulum-associated, Interferon-inducible) inhibits the replication of a broad spectrum of viruses by several diverse mechanisms. The protein was first identified in 2001, when it was found to be the product of an IFN gamma-inducible gene (1).
Viperin is encoded by the RSAD2 gene, and is composed of three distinct domains. The central domain and C-terminal domain are highly conserved, whilst the N-terminal domain shows variability in length and sequence between species, and is necessary for the correct localization and function of the protein. The central domain contains an S-Adenosyl-L-Methionine (SAM) domain, which has a CX3CX2C motif that is involved in iron-sulphur cluster binding and is critical for the conformational stability of the protein (2).
Many experiments have been carried out to try and establish the mechanism by which Viperin performs its...