Wolfson J S, Hooper D C, Swartz M N, McHugh G L
J Bacteriol. 1982 Oct;152(1):338-44. doi: 10.1128/jb.152.1.338-344.1982.
The constructed plasmid pBR322 and the native plasmid pMG110 were eliminated (cured) from growing Escherichia coli cells by the antagonism of the B subunit of the bacterial enzyme DNA gyrase. The antagonism may be by the growth of cells (i) at semipermissive temperatures in a bacterial mutant containing a thermolabile gyrase B subunit or (ii) at semipermissive concentrations of coumermycin A1, an antibiotic that specifically inhibits the B subunit of DNA gyrase. The kinetics of plasmid elimination indicate that plasmid loss occurs too rapidly to be explained solely by the faster growth of that plasmid-free bacteria and, therefore, represents interference with plasmid maintenance.
通过细菌酶DNA促旋酶B亚基的拮抗作用,从生长的大肠杆菌细胞中消除(治愈)构建的质粒pBR322和天然质粒pMG110。这种拮抗作用可能是通过以下方式实现的:(i)在含有热不稳定促旋酶B亚基的细菌突变体中,于半允许温度下培养细胞;(ii)在香豆霉素A1(一种特异性抑制DNA促旋酶B亚基的抗生素)的半允许浓度下培养细胞。质粒消除的动力学表明,质粒丢失发生得太快,无法仅用无质粒细菌的更快生长来解释,因此,这代表了对质粒维持的干扰。