Poly (ADP-Ribosylation) and DNA Topoisomerase I in Different Cell Lines
With his discovery that the Escherichia coli chromosome was circular, John Cairns first pointed out the need for a swivel in DNA replication (1). In eukaryotes, type I DNA topoisomerase has the enzymatic properties necessary to serve as such a swivel. DNA replication would introduce positive supertwists ahead of the replication fork; DNA topoisomerase I has the capacity to unwind such positively supertwisted DNA (2, 3). For this reason, a role for topoisomerase I in replication has been suggested by many workers (2, 3). Recent biological and phenomenological data have also led to the suggestion that type I DNA topoisomerase may be involved in catalyzing DNA strand exchange under certain conditions (4). The mechanisms by which the activity of such a potentially important enzyme may be modulated are of obvious interest.
KeywordsYeast Extract Chinese Hamster Ovary Cell Replication Fork Sister Chromatid Exchange Strand Exchange
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- 2.Wang, J.C. (1981) in; The Enzymes, pp. 331, Boyer, P.D., ed., Academic Press, New York.Google Scholar
- 6.Hayaishi, O. and Ueda, K. (eds.) (1982) ADP-Ribosylation Reactions, Biology and Medicine, Academic Press, New York.Google Scholar
- 13.Bollum, F.J. (1978) Adv. Enzymol, Meister, A., ed., 47, 347.Google Scholar
- 20.Miwa, M. and Sugimura, T. (1982) in: ADP-Ribosylation Reactions Biology and Medicine, pp. 263, (Hayaishi, O. and Ueda, K., eds., Academic Press, New York.Google Scholar
- 27.Burzio, K. and Koide, S.S. (1970) FEBS Lett. 26, 181.Google Scholar