Determining proteins responsible for the host range of potyviruses

The host range of a virus is important as it determines the characteristics of the virus and the distribution of the virus. The aim of this study was to use molecular dynamics simulations to model the interaction of specific virus proteins with plant proteins. Then validate these results through a yeast two-hybrid assay. The nerine yellow stripe virus's (NeYSV) host range is unknown. However, the tobacco etch virus (TEV) is well studied and its hosts include Nicotiana benthamiana and Arabidopsis. The NIa-pro of the TEV virus is predicted to interact with a variety of host proteins. This includes the protein SAHH2 which plays an important role in the creating siRNA, which defend against plant viruses. Potyviral proteins that interact with SAHH disable RNA silencing. This allows a virus to resist the hosts defences and become virulent, expanding the host range. This study modeled the interaction of NIa-pro from NeYSV with the SAHH proteins from N. benthamiana and Arabidopsis. The molecular dynamics results suggested that NeYSV NIa-pro would not bind to Arabidopsis SAHH2 or NbSAHH, suggesting that neither plants are suitable hosts of NeYSV. However, the molecular dynamics results showed that TEV NIa-pro would bind to Arabidopsis SAHH2, supporting previous studies, but not NbSAHH. As both of these plants are hosts of TEV the interaction between NIa-pro and SAHH protein cannot be a determinant of host range. Due to auto-activation, caused by NIa-pro, the molecular dynamics result were not able to be verified through the use of a yeast two-hybrid assay.