title: RNA replication by Q beta replicase: a working model.
abstract: Two classes of RNA ligands that bound to separate, high affinity nucleic acid binding sites on Q beta replicase were previously identified. RNA ligands to the two sites, referred to as site I and site II, were used to investigate the molecular mechanism of RNA replication employed by the four-subunit replicase. Replication inhibition by site I- and site II-specific ligands defined two subsets of replicatable RNAs. When provided with appropriate 3' ends, ligands to either site served as replication templates. UV crosslinking experiments revealed that site I is associated with the S1 subunit, site II with elongation factor Tu, and polymerization with the viral subunit of the holoenzyme. These results provide the framework for a three site model describing template recognition and product strand initiation by Q beta replicase.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder 80309, USA.
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: L
authors.initials: L
authors.lastname: Gold
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D003432:Cross-Linking Reagents; D007700:Kinetics; D008024:Ligands; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D011777:Q beta Replicase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis*; D012194:RNA-Directed DNA Polymerase; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D012093:Replicon; D013698:Templates, Genetic; D014466:Ultraviolet Rays; D014544:Uridine Triphosphate / Q000378:metabolism; D014780:Viruses / Q000201:enzymology
chemical_list: D003432:Cross-Linking Reagents; D008024:Ligands; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D012313:RNA; D011777:Q beta Replicase; D012194:RNA-Directed DNA Polymerase; D010444:Peptide Elongation Factor Tu; D014544:Uridine Triphosphate