The Infidelity of Avian Myeloblastosis Virus Deoxyribonucleic Acid Polymerase in Polynucleotide Replication

摘要: Abstract We have studied the accuracy of DNA synthesis in vitro by purified avian myeloblastosis virus (AMV) polymerase ("reverse transcriptase") using synthetic polynucleotide templates. The enzyme catalyzes incorporation an exceptionally large number incorrectly paired bases when copying ribopolynucleotide and deoxyribopolynucleotide frequency error is approximately 1 600 homopolymer templates 6000 alternating copolymer product reaction, a template polyriboadenylic acid 2500 nucleotides long hybridized to initiator oligodeoxythymidylate 12 18 was analyzed velocity sedimentation equilibrium density gradient centrifugation. results indicate that: (a) entire length given copied; (b) base-paired are integral part product; (c) these errors randomly distributed. Polyacrylamide gel electrophoretic analysis showed two subunits, α β. correct incorrect catalyzed active subunit appears be not influenced inactive β subunit. has no detectable exoor endodeoxyribonuclease activity. AMV exhibits identical requirements for nucleotides. rate function termini, Mg2+ concentration, time incubation, or amount enzyme. is, however, dependent on type ratio reaction mixture. If this from makes similar vivo may mutagenic.