Measurement of poliovirus RNA polymerase binding to poliovirion and nonviral RNAs using a filter-binding assay.

AUTOR(ES)

Oberste, M S

RESUMO

The binding of the purified poliovirus RNA-dependent RNA polymerase to viral and nonviral RNAs was studied using a protein-RNA nitrocellulose filter binding assay. A cellular poly(A)-binding protein was found in viral polymerase preparations, but was easily separated from the polymerase by chromatography on poly(A) Sepharose. Optimal conditions for the binding of purified polymerase (fraction 5-PAS) to 32P-labeled poliovirion RNA were determined. The binding of purified polymerase to 32P-labeled ribohomopolymeric RNAs was examined, and the order of binding observed was poly(G) much much greater than poly(U) greater than poly(C) greater than poly(A). In competitive binding studies, the polymerase bound with equal efficiency to virion RNA and to a subgenomic transcript which contained the 3' end of the genome. The polymerase bound to 18S ribosomal RNA and to globin mRNA equally well, but with a five-fold lower affinity than to virus-specific RNAs. The results suggest that the polymerase exhibits sequence specificity in binding and that polymerase binding sites in poliovirus RNA may contain (G- and/or U)-rich sequences.

Documentos Relacionados

• Purification of a cellular, double-stranded DNA-binding protein required for initiation of adenovirus DNA replication by using a rapid filter-binding assay.
• Filter-binding assay for covalent DNA-protein complexes: adenovirus DNA-terminal protein complex.
• Reaction of poliovirus RNAs with antibodies to double-stranded RNA demonstrated by an immunochemical binding assay.
• Poliovirus RNA-Dependent RNA Polymerase Synthesizes Full-Length Copies of Poliovirion RNA, Cellular mRNA, and Several Plant Virus RNAs In Vitro
• Poliovirus RNA-dependent RNA polymerase and host cell protein synthesize product RNA twice the size of poliovirion RNA in vitro.