Virus-specific proteins associated with the replication complex of poliovirus RNA.

The poliovirus replication complex was isolated and purified from infected HeLa S3 cells. Preparations with RNA-dependent RNA polymerase activity were concentrated 200- and 1000-fold with respect to the original virus and total protein content. The enzyme activity was found to be associated with the proteins NCVPI, 2, 3, 4, (5), 6 and VPl/NCVPx. The structural proteins VP2, 3 and 4 were not present. Addition of cycloheximide to infected cells resulted in a decrease in the in vitro polymerase activity and a loss in NCVPI content. Treatment of the infected cells with toloylsulphonyl-phenylalanine chloromethyl ketone (TPCK) and iodoacetamide (IAA) led to an inhibition of in vivo RNA synthesis. The 750 g supernatant fluids obtained from extracts of these cells were able to block RNA synthesis in vitro. Electrophoretic profiles of the respective protein compositions indicate that large virus precursor proteins are responsible for the inhibition of poliovirus RNA synthesis in vivo and in vitro.