大肠杆菌类核的形状与压实

Shape and compaction of Escherichia coli nucleoids.

作者信息

Zimmerman Steven B

机构信息

Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0560, USA.

出版信息

J Struct Biol. 2006 Nov;156(2):255-61. doi: 10.1016/j.jsb.2006.03.022. Epub 2006 Apr 27.

DOI:10.1016/j.jsb.2006.03.022

PMID:16697220

Abstract

The genomic DNA in cells of Escherichia coli is localized in one or two compact, phase-like regions with characteristic shapes. Nucleoids undergo progressive changes in shape and compaction in the presence of drugs such as chloramphenicol or puromycin. Forces which influence nucleoid shape and compaction are reviewed, with particular emphasis on crowding effects of the cytoplasm and confinement effects of the cell envelope. Based in part on the theory of Kornyshev and Leikin for interaction between DNA duplexes, the folding of DNA caused by binding of DNA-associated proteins is suggested to antagonize DNA condensation and, thereby, increase access to DNA sequences. These views are incorporated into a working model for nucleoid organization.

摘要

大肠杆菌细胞中的基因组DNA定位于一个或两个具有特征形状的致密、相状区域。在氯霉素或嘌呤霉素等药物存在的情况下，类核体会经历形状和压缩程度的逐步变化。本文综述了影响类核形状和压缩程度的力，特别强调了细胞质的拥挤效应和细胞膜的限制效应。部分基于科尔尼舍夫和列伊金提出的DNA双链相互作用理论，推测与DNA相关的蛋白质结合导致的DNA折叠会对抗DNA凝聚，从而增加对DNA序列的可及性。这些观点被纳入一个类核组织的工作模型中。