Purification and properties of the ribonucleic acid-dependent ribonucleic acid polymerase from Halobacterium cutirubrum.
1. The RNA-dependent RNA polymerase from Halobacterium cutirubrum was purified to electrophoretic homogeneity. 2. It requires a single-stranded molecule of RNA or polyribonucleotide as template. 3. Nearest-neighbour analyses of the products formed on random poly(A,U) or alternating poly(A-U) templates and base analysis of the product of synthesis directed by wheat-germ RNA prove that the template is copied accurately. 4. The enzyme initiates new chains with purine ribonucleoside triphosphates. 5. Sucrose-density-gradient analysis of the product indicates that it has a size distribution similar to that of the template. 6. Preliminary amino acid analysis of the RNA-dependent polymerase shows that it contains much less serine than either of the subunits of H. cutirubrum DNA-dependent RNA polymerase. 7. The RNA-dependent enzyme is unable to substitute for either subunit of the DNA-dependent polymerase, and both the latter are devoid of RNA-dependent activity.
D000596:Amino Acids / Q000032:analysis; D001483:Base Sequence; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D012321:DNA-Directed RNA Polymerases / Q000032:analysis / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D006217:Halobacterium / Q000201:enzymology*; D010759:Phosphorus Isotopes; D012329:RNA, Bacterial; D012694:Serine / Q000032:analysis; D013698:Templates, Genetic
D000596:Amino Acids; D010759:Phosphorus Isotopes; D012329:RNA, Bacterial; D012694:Serine; D012321:DNA-Directed RNA Polymerases