Hochmannová J, Nesvera J, Stokrová J
Folia Microbiol (Praha). 1980;25(1):11-5. doi: 10.1007/BF02876392.
Minicells of Escherichia coli P678-54 containing plasmid RIdrd19 were submitted to careful controlled lysis. By sedimentation of the resulting lyzate in a sucrose gradient, the material absorbing at 260 nm was separated into three distinct bands. Among the most rapidly sedimenting particles, double-stranded topological circles of DNA attached to patches of membrane were visualized by electron microscopy, while single-stranded molecules (probably RNA) with associated proteins were detected in the medium band. Covalently closed and open circles of the RIdrd19 DNA were found at the top of the gradient. Their contour lengths correspond to the size of the DNA sedimenting together with the membrane in the first peak. This finding implies a direct intracellular interaction between RIdrd19 DNA and membrane in E. coli minicelle.
含有质粒RIdrd19的大肠杆菌P678 - 54微小细胞被进行了仔细的受控裂解。通过在蔗糖梯度中对所得裂解物进行沉降，在260nm处有吸收的物质被分离成三条不同的带。在沉降最快的颗粒中，通过电子显微镜观察到附着有膜片的双链拓扑DNA环，而在中间带中检测到带有相关蛋白质的单链分子（可能是RNA）。在梯度顶部发现了RIdrd19 DNA的共价闭合环和开环。它们的轮廓长度与在第一个峰中与膜一起沉降的DNA大小相对应。这一发现意味着在大肠杆菌微小细胞中RIdrd19 DNA与膜之间存在直接的细胞内相互作用。
