The central and C-terminal domains of VPg of Clover yellow vein virus are important for VPg–HCPro and VPg–VPg interactions

Abstract

Interactions between the major proteins of Clover yellow vein virus (ClYVV) were investigated using a GAL4 transcription activator-based yeast two-hybrid system (YTHS). Self-interactions manifested by VPg and HCPro and an interaction between NIb and NIaPro were observed in ClYVV. In addition, a strong HCPro-VPg interaction was detected by both YTHS and by in vitro far-Western blot analysis in ClYVV. A potyvirus HCPro-VPg interaction has not been reported previously. Using YTHS, domains in ClYVV for the VPg self-interaction and the HCPro-VPg interaction were mapped. The VPg C-terminal region (38 amino acids) was important for the VPg-VPg interaction and the central 19 amino acids were needed for the HCPro-VPg interaction.