Mechanism of ATP inhibition of mammalian type I DNA topoisomerase: DNA binding, cleavage, and rejoining are insensitive to ATP.


A general, unrefined mechanism of type I DNA topoisomerase action involves several steps including DNA binding, single-strand scission, strand passage resealing, and, possibly, readoption of an active enzyme conformation. None of these steps requires an energy cofactor; however, we have shown previously that several mammalian type I topoisomerases are, in… (More)