期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：12
页码：4892-4896
DOI：10.1073/pnas.71.12.4892
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Evidence is presented that DNA polymerase of avian myeloblastosis virus has an obligatory zinc requirement for activity. Previous studies indicate that the purified polymerase contains zinc in a stoichiometry of about 1 g-atom/mole. We now find that the enzyme-bound zinc is exchangeable with radioactive 65Zn; after isoelectric focusing, the radioactive 65Zn is coincident with polymerase activity. Dialysis of the 65Zn-labeled polymerase against the chelator, 1,10-phenanthroline, results in a progressive loss of radioactive 65Zn and polymerase activity. Thereupon, incubation of the inactivated enzyme with Zn2+ fully restores activity. Thus, the DNA polymerase present in an oncogenic RNA virus, like animal DNA polymerases, can be rigorously classified as a zinc metalloenzyme. DNA polymerase of avian myeloblastosis virus is inactivated by 1,10-phenanthroline at a much faster rate than the bacterial and animal DNA polymerases that have been tested. It may, therefore, be possible to inactivate selectively DNA polymerases from animal tumor viruses by brief exposure to appropriate metal chelators.
关键词：avian myeloblastosis virus ; RNA-directed DNA polymerase ; RNA virus
