Viral counterattack against the host innate immune system.

Paramyxoviruses evade antiviral immune response using a small nonstructural protein, V, which binds to the host dsRNA sensor MDA5 and prevents it from activating the interferon signaling pathway. A recent crystal structure of the V protein in complex with MDA5, published in Science, revealed that V disrupts the structure of MDA5 and is integrated into the MDA5 protein fold, providing an intriguing new example of viral mimicry as a countermeasure against the host immune system.