"In vitro" binding of cellular, alpha-amanitin sensitive, RNA polymerase to infectious, mengovirus-induced double-stranded RNA

A cellular, α-Amanitin sensitive, RNA polymerase from mouse L cells binds “in vitro” to Mengovirus-induced, double-stranded (ds) RNA. Formation of the “enzyme-ds RNA” complex was studied by the nitrocellulose filter technique. Reaction strongly depends on K+/(NH)++ and Mn++/Mg++ concentration, occurs optimally at 37°C, is linear with time up to 10 minutes, and is inhibited by a rifamycin derivative AF/013. Competition experiments demonstrated that neither heat-denatured Mengovirus RF nor single-stranded ribonucleotides interfere with complex formation, whereas the double-helical form same RNAs (native RF, Poly I:C; Poly A:U) efficiently compete with Mengovirus RF for cellular polymerase. These results seem to indicate that the double-helical nature of the template is essential for binding to occur.