To obtain FHV replicase preparation, BY4741 yeast strain was transformed with plasmid pGAD/Cup/FHV/proteinA/C-term/ HA/FLAG and pESC-His-GAL1::FHVRNA1framshift. After selection of transformed yeast on SC-LH 2 plates, yeast were pre-grown overnight in selective media containing 2% glucose at 29uC. After centrifugation at 2,000 rpm for 3 min and washing pellet with selective media containing 2% galactose, yeast were grown 36 hours at 29uC in SC-LH 2 media containing 2% galactose and 50 mM CuSO 4 to induce FHV RNA replication. Affinity-purification was done similarly as for tombusvirus, except for using different buffers: homogenization buffer consisted of 