Accessory Proteins
Multiple ZAP cofactors have been reported to be required for antiviral activity. However the E3 ubiquitin ligase TRIM25 (tripartite motif protein 25) and KHNYN (KH-like and NYN domain-containing protein) have the most well documented evidence. TRIM25 has been shown to promote ZAP activity by multimerization through its RING domain whereas KHNYN acts an active nuclease for RNA cleavage which can be partially replaced functionally by its homolog N4BP1. == Classification of ZAP sensitive viruses ==