Decatenating activity of Escherichia coli DNA gyrase and topoisomerases I and III during oriC and pBR322 DNA replication in vitro.

摘要: oriC and pBR322 DNA replication, reconstituted with purified replication proteins, has been used to study the functional activities of Escherichia coli topoisomerase I, gyrase, III during final stages replication. In system, gyrase-catalyzed decatenation daughter molecules was very inefficient, whereas could catalyze complete decatenation. almost all be decatenated by gyrase alone in absence salt. Decatenation system completely inhibited, without a concomitant inhibition synthesis, addition physiological concentrations Topoisomerase III, however, decatenate even presence high A similar effect not observed because salt inhibited synthesis. I incapable catalyzing under any conditions examined either or system. The systems resulted only an