{"title":"Determination of DNA architecture of bacteria under various types of stress, methodological approaches, problems, and solutions.","authors":"Yu F Krupyanskii","doi":"10.1007/s12551-023-01122-0","DOIUrl":null,"url":null,"abstract":"<p><p>Actively growing cells maintain a dynamic, far from equilibrium order through metabolism. Under starvation stress or under stress of exposure to the analog of the anabiosis autoinducer (4-hexylresorcinol), cells go into a dormant state (almost complete lack of metabolism) or even into a mummified state. In a dormant state, cells are forced to use the physical mechanisms of DNA protection. The architecture of DNA in the dormant and mummified state of cells was studied by x-ray diffraction of synchrotron radiation and transmission electron microscopy (TEM). Diffraction experiments indicate the appearance of an ordered organization of DNA. TEM made it possible to visualize the type of DNA ordering. Intracellular nanocrystalline, liquid-crystalline, and folded nucleosome-like structures of DNA have been found. The structure of DNA within a cell in an anabiotic dormant state and dormant state (starvation stress) coincides (forms nanocrystalline structures). Data suggest the universality of DNA condensation by a protein Dps for a dormant state, regardless of the type of stress. The mummified state is very different in structure from the dormant state (has no ordering within a cell). It turned out that it is possible to visualize DNA conformation in toroidal and liquid crystal structures in which there is either no or a very small amount of the Dps protein. Observation of the DNA conformation in nanocrystals and folded nucleosome-like structures so far has been inconclusive. The methodological advances described will facilitate high-resolution visualization of the DNA conformation in the near future.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10643406/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biophysical reviews","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s12551-023-01122-0","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/10/1 0:00:00","PubModel":"eCollection","JCR":"Q1","JCRName":"BIOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Actively growing cells maintain a dynamic, far from equilibrium order through metabolism. Under starvation stress or under stress of exposure to the analog of the anabiosis autoinducer (4-hexylresorcinol), cells go into a dormant state (almost complete lack of metabolism) or even into a mummified state. In a dormant state, cells are forced to use the physical mechanisms of DNA protection. The architecture of DNA in the dormant and mummified state of cells was studied by x-ray diffraction of synchrotron radiation and transmission electron microscopy (TEM). Diffraction experiments indicate the appearance of an ordered organization of DNA. TEM made it possible to visualize the type of DNA ordering. Intracellular nanocrystalline, liquid-crystalline, and folded nucleosome-like structures of DNA have been found. The structure of DNA within a cell in an anabiotic dormant state and dormant state (starvation stress) coincides (forms nanocrystalline structures). Data suggest the universality of DNA condensation by a protein Dps for a dormant state, regardless of the type of stress. The mummified state is very different in structure from the dormant state (has no ordering within a cell). It turned out that it is possible to visualize DNA conformation in toroidal and liquid crystal structures in which there is either no or a very small amount of the Dps protein. Observation of the DNA conformation in nanocrystals and folded nucleosome-like structures so far has been inconclusive. The methodological advances described will facilitate high-resolution visualization of the DNA conformation in the near future.
期刊介绍:
Biophysical Reviews aims to publish critical and timely reviews from key figures in the field of biophysics. The bulk of the reviews that are currently published are from invited authors, but the journal is also open for non-solicited reviews. Interested authors are encouraged to discuss the possibility of contributing a review with the Editor-in-Chief prior to submission. Through publishing reviews on biophysics, the editors of the journal hope to illustrate the great power and potential of physical techniques in the biological sciences, they aim to stimulate the discussion and promote further research and would like to educate and enthuse basic researcher scientists and students of biophysics. Biophysical Reviews covers the entire field of biophysics, generally defined as the science of describing and defining biological phenomenon using the concepts and the techniques of physics. This includes but is not limited by such areas as: - Bioinformatics - Biophysical methods and instrumentation - Medical biophysics - Biosystems - Cell biophysics and organization - Macromolecules: dynamics, structures and interactions - Single molecule biophysics - Membrane biophysics, channels and transportation