Saiki T, Kohno K, Goshima N, Kano Y, Imamoto F
Department of Molecular Genetics, Kyoto Pharmaceutical University.
J Biochem. 1994 Dec;116(6):1208-11. doi: 10.1093/oxfordjournals.jbchem.a124665.
A plasmid carrying both gyrA and gyrB genes (pTS7) and a plasmid without the gyr gene (pTS4) were constructed. Introduction of pTS7 into the YK1100 (wild-type) cells resulted in an increase in the level of gyrA and gyrB mRNA by 5- to 6-fold over the level of the control transformant with pTS4. In the transformant cells carrying pTS7, the reporter plasmid pGP241, which is compatible with pTS plasmids, was significantly more highly negatively supercoiled than in the transformant with pTS4. The activity of DNA gyrase to supercoil the relaxed pGP241 DNA was 4-8 times higher with the S-30 extract from the transformant carrying pTS7 than with the extract from the transformant with pTS4.
构建了携带gyrA和gyrB基因的质粒（pTS7）以及不含gyr基因的质粒（pTS4）。将pTS7导入YK1100（野生型）细胞后，gyrA和gyrB mRNA的水平比携带pTS4的对照转化体提高了5至6倍。在携带pTS7的转化体细胞中，与pTS质粒兼容的报告质粒pGP241的负超螺旋程度明显高于携带pTS4的转化体。携带pTS7的转化体的S-30提取物使松弛的pGP241 DNA超螺旋的DNA促旋酶活性比携带pTS4的转化体的提取物高4至8倍。
