Papain-like protease p48 is a cysteine protease of the peptidase family C8. a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) ATP + H2O = ADP + H(+) + phosphate Papain-like protease p48 is autocatalytically processed. The putative RNA-directed RNA polymerase/helicase is probably further processed (By similarity). Hypoviruses induce hypovirulence in their fungal host Cryphonectria parasitica. The consequence is attenuation of the related fungal disease, chestnut blight, that causes cankers that enlarge and kill branches and trunks. The virus-like genetic elements consist of cytoplasmically replicating double-stranded RNA. CHV-1 strain Euro7 is a mild hypovirulent strain. In the C-terminal section; belongs to the DEAD box helicase family.