InterPro domain: IPR036673

Cyanovirin-N (CV-N) is an 11kDa protein from the cyanobacterium Nostoc ellipsosporum that displays virucidal activity against several viruses, including human immunodeficiency virus (AIDS). The virucidal activity of CV-N is mediated through specific high-affinity interactions with the viral surface envelope glycoproteins gp120 and gp41, as well as to high-mannose oligosaccharides found on the HIV envelope [ 1 ]. In addition, CV-N is active against rhinoviruses, human parainfluenza virus, respiratory syncytial virus, and enteric viruses. The virucidal activity of CV-N against influenza virus is directed towards viral haemagglutinin [ 2 ].

The CV-N domain is evolutionarily conserved and occurs as a protein module in eukaryotes [ 3 ]. CV-N has a complex fold composed of a duplication of a tandem repeat of two homologous motifs comprising three-stranded beta-sheet and beta-hairpins [ 4 ].

1. Cyanovirin-N: a sugar-binding antiviral protein with a new twist. Cell. Mol. Life Sci. 60, 277-87
2. Potent anti-influenza activity of cyanovirin-N and interactions with viral hemagglutinin. Antimicrob. Agents Chemother. 47, 2518-25
3. The anti-HIV cyanovirin-N domain is evolutionarily conserved and occurs as a protein module in eukaryotes. Proteins 60, 670-8
4. Structures of the complexes of a potent anti-HIV protein cyanovirin-N and high mannose oligosaccharides. J. Biol. Chem. 277, 34336-42