Park S M, Koo H S
Department of Biochemistry, College of Science, Yonsei University, Seoul, South Korea.
Biochim Biophys Acta. 1994 Sep 13;1219(1):47-54. doi: 10.1016/0167-4781(94)90245-3.
DNA topoisomerase I was partially purified from Caenorhabditis elegans worms. The enzyme is a 95 kDa polypeptide and its proteolytically degraded form of 70 kDa was also observed. The enzyme removed not only negative but also positive DNA supercoils. The optimum salt concentration for the DNA relaxation activity was 100 mM KCl, and divalent cations were not required but stimulated the activity. The DNA relaxation activity was weakly sensitive to 125 microM camptothecin but was completely inhibited by 125 microM berenil.
