Biochemistry of Bacterial Type I DNA Topoisomerases

Biochemistry of Bacterial Type I DNA Topoisomerases Book Chapter

Tse-Dinh, YC. (1994). Biochemistry of Bacterial Type I DNA Topoisomerases . 29 21-37. 10.1016/S1054-3589(08)60538-4

This chapter discusses the biochemistry of bacterial type I DNA topoisomerases. The characteristic that distinguishes these bacterial type I topoisomerases from the eukaryotic type I topoisomerases is the requirement of Mg2+ and the inability to relax positively supercoiled DNA. A novel type I topoisomerase activity, reverse gyrase, was purified from the extremely thermophilic archaebacteriae Sulfolobus acidocaldarius and Desulfurococcus amylolyticus (D. amylolyticus). It can utilize the energy from adenosine-5'-triphosphate (ATP) hydrolysis to introduce positive supercoiling into DNA. Similar reverse gyrase activity was detected in 12 other phylogenetically distant hyperthermophilic archaebacteria and four strains of the extremely thermophilic eubacteria Thermotogales, suggesting that this topoisomerase activity is required for DNA duplex stability at high temperatures. A second distinct type I topoisomerase activity was purified from D. amylolyticus. It is an ATP independent relaxing topoisomerase and was named topoisomerase III to distinguish it from reverse gyrase, for which the designation archaebactetial topoisomerase I has been proposed. © 1994, Academic Press, Inc.