Structure And Stabilization Of The Bacterial Nucleoid

细菌核的结构和稳定性

• 批准号: 6664158
• 负责人: Steven C. Zimmerman
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6664158
• 关键词: Escherichia coli; bacterial DNA; bacterial RNA; bacterial genetics; cell component structure /function; cell nucleus; chloramphenicol; formaldehyde; nucleic acid denaturation; nucleoproteins; phase contrast microscopy; polylysine; protein sequence; tissue /cell preparation

The DNA of bacteria is localized in a few compact bodies per cell known as nucleoids. Control of compaction offers a virtually unexplored means of interacting with and potentially controlling bacterial growth. We have previously developed quantitative procedures to assay factors that are involved in nucleoid compaction in Escherichia coli. One of these factors, known for 30 years but never identified, is characterized by its RNase-sensitivity. By use of the new assay procedures, this RNase-sensitive component has been identified as the ribosomal link in cotranslational insertion linkages between the nucleoidal DNA and the cell envelope. The rounded nucleoids ("cm-nucleoids)that are formed upon exposure of E. coli to chloramphenicol, as well as under several other conditions, are of particular interest. Cm-nucleoids are extraordinarily stable to denaturation and appear to be formed by a relatively direct and efficiently reversible conversion from normal nucleoids, offering potential insights into the unknown structure of the normal nucleoid. Although a hollow spherical model had been repeatedly presented for cm-nucleoids by another laboratory, that model is unable to account for the light microscope appearance of a significant fraction of cm-nucleoids. A new type of curved toroidal structure is proposed for cm-nucleoids which can rationalize the previously discordant observations.

细菌的DNA被定位在每个细胞称为类核的几个致密体中。控制压实提供了一种几乎未开发的与细菌生长相互作用和潜在控制的方法。