Recombinant Rubella virus Non-structural polyprotein p200, partial

Probable principal replicase for the negative-strand DNA, which replicates the 40S (+) genomic RNA into (-) antigenomic RNA. It cannot replicate the (-) into (+) until cleaved into p150 and p90 mature proteins.; Protease that cleaves the precursor polyprotein into two mature products. Together with RNA-directed RNA polymerase p90, replicates the 40S genomic and antigenomic RNA by recognizing replications specific signals. The heterodimer P150/p90 is probably the principal replicase for positive-strand genomic RNA and the 24S subgenomic RNA, which codes for structural proteins. Responsible for the mRNA-capping of the viral mRNAs. This function is necessary since all viral RNAs are synthesized in the cytoplasm, and host capping enzymes are restricted to the nucleus. Forms fibers late in the infection that may be involved in cell-to-cell spread of the virus RNA in the absence of virus particle formation.; Together with protease/methyltransferase p150, replicates the 40S genomic and antigenomic RNA by recognizing replications specific signals. The heterodimer P150/p90 is probably the principal replicase for positive-strand genomic RNA and the 24S subgenomic RNA, which codes for structural proteins. A helicase activity is probably also present.