On the fidelity of DNA replication. Enzyme activities associated with DNA polymerases from RNA tumor viruses.


DNA polymerase from RNA tumor viruses ("reverse transcriptase") has ...
DNA polymerase from RNA tumor viruses ("reverse transcriptase") has been analyzed for activities which have been associated with other DNA polymerases. Homogeneous DNA polymerase from avian myeoblastosis virus catalyzes pyrophosphate exchange and pyrophosphorolysis. Pyrophosphate exchange is dependent on a template and is base-specific. With avian myeloblastosis virus DNA polymerase, ribonucleotide templates are more efficient for synthesis while deoxyribonucleotide templates are more effective for pyrophosphate exchange. Synthesis, pyrophosphate exchange, and pyrophosphorolysis were inhibited by the chelating agent 1,10-phenanthroline, suggesting that enzyme-bound zinc is required for each of these reactions. The pyrophosphate exchange reaction was also demonstrated with the DNA polymerase from a mutant of Rous sarcoma virus that possesses a temperature-sensitive DNA polymerase. The pyrophosphate exchange reaction with the mutant polymerase is temperature-sensitive which demonstrates that pyrophosphate exchange is indeed catalyzed by the viral DNA polymerase and that the same mutation effects both DNA polymerase and pyrophosphatase activity. Unlike Escherichia coli DNA polymerase I, the DNA polymerase from avian myeloblastosis virus fails to degrade polydeoxyribonucleotides or to convert deoxynucleoside triphosphates into monophosphates. This lack of hydrolytic activities in avian myeoblastosis DNA polymerase should facilitate kinetic studies on the mechanism of DNA synthesis by this enzyme.




new topics/pols set partial results complete validated


No results available for this paper.

Entry validated by:

Using Polbase tables:


Tables may be sorted by clicking on any of the column titles. A second click reverses the sort order. <Ctrl> + click on the column titles to sort by more than one column (e.g. family then name).


It is also possible to filter the table by typing into the search box above the table. This will instantly hide lines from the table that do not contain your search text.