Characterization of an RNA-dependent RNA polymerase activity associated with measles virus

Abstract

An RNA-dependent RNA polymerase activity was found copurifying with measles virus infectivity and complement-fixing antigen in 3 [African green monkey kidney] Vero cell-grown variants of measles virus: the attenuated Edmonston B strain, the natural nonattenuated Edmonston strain and a subacute sclerosing panencephalitis isolate, IP-3. Incubation of purified measles virions with immunoglobulin G derived from sera of monkeys hyperimmunized against measles specifically removes activity sedimenting in the density region of measles virions. The requirements of the reaction, which is RNase sensitive, are similar to those reported for other paramyxovirus-associated activities, including detergent, divalent cation, ribonucleoside triphosphates and a reducing agent. The size classes of RNA synthesized correspond to those found in measles-infected cells, including 50, 35 and 16 to 20S. The product RNA of the Edmonston B virus-stimulated reaction was rendered RNase resistant by annealing with RNA extracted from purified Edmonston B virions. RNA from uninfected Vero cells was ineffective in the annealing reaction.