Structural basis of RNA recognition and activation by innate immune receptor RIG-I

The binding of helicase to viral RNA and the resulting activation of the retinoic acid inducible gene-I (RIG-I) are central to the innate immune response to viral infection. The structure of the RIG-I helicase domain with its repressor domain, in complex with double-stranded RNA, has now been determined. The structure suggests a mechanism of dsRNA translocation. Because RIG-I is homologous to many other helicases, such as Dicer of the RNAi machinery and the FANCM helicases involved in DNA repair, the structure should prove relevant to helicases in these other biological processes.