Harvard Biophysics Program, Harvard Medical School, Boston, MA, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
Trends Genet. 2015 Mar;31(3):164-73. doi: 10.1016/j.tig.2015.01.003. Epub 2015 Feb 11.
All organisms must dramatically compact their genomes to accommodate DNA within the cell. Bacteria use a set of DNA-binding proteins with low sequence specificity called nucleoid-associated proteins (NAPs) to assist in chromosome condensation and organization. By bending or bridging DNA, NAPs also facilitate chromosome segregation and regulate gene expression. Over the past decade, emerging single-molecule and chromosome conformation capture techniques have investigated the molecular mechanisms by which NAPs remodel and organize the bacterial chromosome. In this review we describe how such approaches reveal the biochemical mechanisms of three NAPs that are believed to facilitate DNA bridging: histone-like nucleoid structuring protein (H-NS), ParB, and structural maintenance of chromosomes (SMC). These three proteins form qualitatively different DNA bridges, leading to varied effects on transcription and chromosome segregation.
所有生物都必须将其基因组大幅压缩，以适应细胞内的 DNA。细菌使用一组序列特异性低的 DNA 结合蛋白，称为核体相关蛋白（NAPs），以协助染色体浓缩和组织。NAP 通过弯曲或桥接 DNA，还促进染色体分离并调节基因表达。在过去的十年中，新兴的单分子和染色体构象捕获技术已经研究了 NAP 重塑和组织细菌染色体的分子机制。在这篇综述中，我们描述了这些方法如何揭示三种被认为有助于 DNA 桥接的 NAP 的生化机制：组蛋白样核体结构蛋白（H-NS）、ParB 和染色体结构维持蛋白（SMC）。这三种蛋白质形成性质不同的 DNA 桥，对转录和染色体分离产生不同的影响。
