RNA replication. The protein possibly functions as an ATP-binding helicase (Probable). a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) ATP + H2O = ADP + H(+) + phosphate The sclerotinia sclerotiorum debilitation-associated virus contains only a single ORF. Belongs to the potexvirus/carlavirus RNA replication protein family.