Abstract
A map for the interactions of the major proteins from Potato virus A (PVA) and Pea seed-borne mosaic virus (PSbMV) (members of the genus Potyvirus, family Potyviridae) was generated using the yeast two-hybrid system (YTHS). Interactions were readily detected with five PVA protein combinations (HCHC, HCCI, VPgVPg, NIaNIb and CPCP) and weak but reproducible interactions were detected for seven additional combinations (P1CI, P3NIb, NIaProNIb, VPgNIa, VPgNIaPro, NIaProNIa and NIaNIa). In PSbMV, readily detectable interactions were found in five protein combinations (HCHC, VPgVPg, VPgNIa, NIaNIa and NIaNIb) and weaker but reproducible interactions were detected for three additional combinations (P3NIa, NIaNIaPro and CPCP). The self-interactions of HC, VPg, NIa and CP and the interactions of VPgNIa, NIaNIaPro and NIaNIb were, therefore, common for the two potyviruses. The multiple protein interactions revealed in this study shed light on the co-ordinated functions of potyviral proteins involved in virus movement and replication.