Presentations

Architecture of condensed DNA

Krupyanskii Y.F., Kovalenko V.V., Loiko N.G., Tereshkin E.V., Generalova A.A., Tereshkina K.B., Sokolova O.S.¹

N. N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, Russia, yuriifkru@gmail.com

¹Lomonosov Moscow State University, Faculty of Biology, Moscow, Russia

DNA in an actively growing cell is organized hierarchically with three levels of DNA compaction. Actively growing cells maintain a dynamic, far-from-equilibrium order through metabolism. Under starvation stress, cells enter a dormant state (virtually no metabolism), conventional biochemical DNA protection mechanisms cease to function, and cells are forced to use physical DNA protection mechanisms. DNA architecture in the nucleoid of dormant cells has been studied using synchrotron radiation diffraction and transmission electron microscopy (TEM). Intracellular nanocrystalline, liquid crystalline, and folded nucleosome-like DNA structures have been detected [1]. Next, we studied changes in DNA architecture under the stress effect of a chemical analogue of the autoinducer of anabiosis (4-hexylresorcinol, 4HR). An increase in the concentration of 4HR causes a transition of some cells to an anabiotic dormant state, and then to a mummified state. Studies of DNA architecture in anabiotic and mummified states show the identity of the DNA structure in the anabiotic state and in the resting state under starvation stress [2,3]. The DNA architecture in the mummified state is very different from the DNA architecture in the anabiotic state [2,3].

References

1. Y.F. Krupyanskii. Determination of DNA architecture of bacteria under various types of stress, methodological approaches, problems, and solutions. Biophysical Reviews, 2023, https://doi.org/10.1007/s12551-023-01122-0

2. .Y.F. Krupyanskii et al. Condensed DNA structure in bacteria subjected to various types of stress. Moscow University Biological Sciences Bulletin, 2023, Vol. 78, Suppl. 1, pp. S45–S49. https://doi.org/10.3103/S0096392523700207

3. Yu. F. Krupyanskii et al. The Structure of DNA in Anabiotic and Mummified Escherichia coli Cells. Russian Journal of Physical Chemistry B, 2024, Vol. 18, No. 4, pp. 1134–1140.

https://doi.org/10.1134/S1990793124700441

• abstract in Russian (PDF)