Liebart J C, Paolozzi L, Camera M G, Pedrini A M, Ghelardini P
Institut Jacques Monod, Paris, France.
Mol Microbiol. 1989 Mar;3(3):269-73. doi: 10.1111/j.1365-2958.1989.tb00171.x.
Many genes of Escherichia coli have been shown to be sensitive to DNA superhelicity. The superhelicity of the chromosome is itself also supercoiling-dependent. We have developed a general strategy for investigating how a particular gene responds to changes in DNA topology. This approach is used to study the E. coli ligase gene. The thermosensitivity of the E. coli ligts251 mutation can be phenotypically suppressed by mutations which map close to, or in, the gyrB gene and which affect the degree of DNA supercoiling. The level of suppression correlates with the degree of DNA relaxation observed, suggesting that the gene encoding the E. coli DNA ligase is activated by relaxation of the chromosomal DNA.
许多大肠杆菌基因已被证明对DNA超螺旋敏感。染色体的超螺旋本身也依赖于超螺旋。我们已经开发出一种通用策略，用于研究特定基因如何响应DNA拓扑结构的变化。该方法用于研究大肠杆菌连接酶基因。大肠杆菌ligts251突变的温度敏感性可以通过位于gyrB基因附近或内部且影响DNA超螺旋程度的突变在表型上得到抑制。抑制水平与观察到的DNA松弛程度相关，这表明编码大肠杆菌DNA连接酶的基因是由染色体DNA的松弛激活的。
