Effect of Rifampin on the Structure and Membrane Attachment of the Nucleoid of Escherichia coli
Effect of Rifampin on the Structure and Membrane Attachment of the Nucleoid of Escherichia coli
复制标题
利福平对大肠杆菌核仁结构和膜附着的影响
DOI：
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发表时间：
1973
影响因子：
3.2
通讯作者：
M. Schaechter
中科院分区：
文献类型：
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作者：
P. Dworsky;M. Schaechter
发现大肠杆菌的脱氧核糖核酸（DNA）附着在细胞膜上约20个点。这是通过用M带（镁-肌氨酸晶体）技术对X射线照射的细胞进行分级分离来确定的。附着点的数量是根据M带中DNA的量与X射线处理引入的双链断裂数量之间的关系计算的。通过用利福平处理细胞，附着点的数量减少了四倍。这种效应显然是由于药物对核糖核酸（RNA）聚合酶的作用，因为药物不影响RNA聚合酶对利福平耐药的突变体。这表明膜上可能有两类DNA附着点，其中一些通过利福平处理去除，而另一些则没有。利福平治疗也导致了未凝聚的孤立的类核，并在轴向外观的类核在切片。结果表明，RNA聚合酶发挥作用，直接或间接，在维持细菌类核的结构，并在其附着到膜的一些。
Deoxyribonucleic acid (DNA) of Escherichia coli was found to be attached to the cell membrane at about 20 points. This was determined by fractionation of X-irradiated cells with the M band (magnesium-Sarkosyl crystals) technique. The number of attachment points was computed from the relationship between the amount of DNA in M bands and the number of double-strand breaks introduced by the X-ray treatment. The number of attachment points was decreased fourfold by treatment of cells with rifampin. This effect was apparently due to the action of the drug on ribonucleic acid (RNA) polymerase since the drug did not affect a mutant whose RNA polymerase is resistant to rifampin. This suggests that there may be two classes of attachment points of DNA on the membrane, some of which are removed by rifampin treatment and some which are not. Rifampin treatment also resulted in the uncondensing of isolated nucleoids and in an axial appearance of the nucleoids in ultrathin sections. The results suggest that RNA polymerase plays a role, direct or indirect, in maintaining the structure of the bacterial nucleoid and in some of its attachment to the membrane.