Ruberti I, Crescenzi F, Paolozzi L, Ghelardini P
Centro di Studio per gli Acidi Nucleici del CNR, Dipartimento di Genetica e Biologica Molecolare, Universitá di Roma La Sapienza, Italy.
Mol Microbiol. 1991 May;5(5):1065-72. doi: 10.1111/j.1365-2958.1991.tb01878.x.
Previous work in our laboratory suggested that DNA topology could be implicated in the regulation of the division gene ftsZ. To settle this question, we have selected and characterized mutants in the gyrB gene able to phenotypically suppress the defects of the ftsZ84 mutation. No strict correlation was found between the degree of plasmid DNA relaxation and the level of suppression of the thermosensitivity of the ftsZ84 strain. Interestingly, the class of mutants that shows maximal suppression is substantially unaffected in DNA topology. In addition, the amount of ftsZ-specific mRNA in this class of mutants is comparable to that present in the ftsZ84 strain. These results hint that the ability of these gyrB mutants to correct the effects of the ftsZ84 mutation is largely unrelated to the function of the GyrB (as a part of DNA gyrase) in the control of DNA superhelicity and suggest hitherto unsuspected interaction between the ftsZ and gyrB gene products.
我们实验室之前的研究表明，DNA拓扑结构可能与分裂基因ftsZ的调控有关。为了解决这个问题，我们筛选并鉴定了gyrB基因中的突变体，这些突变体能够在表型上抑制ftsZ84突变的缺陷。在质粒DNA松弛程度与ftsZ84菌株热敏感性抑制水平之间未发现严格的相关性。有趣的是，表现出最大抑制作用的突变体类别在DNA拓扑结构上基本未受影响。此外，这类突变体中ftsZ特异性mRNA的量与ftsZ84菌株中的相当。这些结果表明，这些gyrB突变体纠正ftsZ84突变效应的能力在很大程度上与GyrB（作为DNA促旋酶的一部分）在控制DNA超螺旋中的功能无关，并提示ftsZ和gyrB基因产物之间存在迄今未被怀疑的相互作用。
