The chromosome of Escherichia Coli (E. coli) is riddled with multi-faceted complexity and its nature of organization is slowly getting recognised. The emergence of chromosome conformation capture techniques and super-resolution microscopy are providing newer ways to explore chromosome organization, and dynamics and its effect on gene expression. Here we combine a beads-on-a-spring polymer-based framework with recently reported high-resolution Hi-C data of E. coli chromosome to develop a comprehensive model of E. coli chromosome at 5 kilo base-pair resolution. The model captures a self-organised chromosome composed of linearly organised genetic loci, and segregated macrodomains within a ring-like helicoid architecture, with no net chirality. Additionally, a genome-wide map identifies multiple chromosomal interaction domains (CIDs) and corroborates well with a transcription-centric model of the E. coli chromosome. The investigation further demonstrates that while only a small fraction of the Hi-C contacts is dictating the underlying chromosomal organization, a random-walk polymer chain devoid of Hi-C encoded contact information would fail to map the key genomic interactions unique to E. coli. Collectively, the present work, integrated with Hi-C interaction, elucidates the organization of bacterial chromosome at multiple scales, ranging from identifying a helical, macro-domain-segregated morphology at coarse-grained scale to a manifestation of CIDs at a fine-grained scale.

中文翻译：

---

在Hi-C集成模型中绘制大肠杆菌染色体的多尺度组织

大肠杆菌（染色体大肠杆菌）是充满了多面的复杂性和其组织的性质慢慢变的认可。染色体构象捕获技术和超分辨率显微镜的出现为探索染色体组织，动力学及其对基因表达的影响提供了更新的方法。在这里，我们结合了基于弹珠聚合物的框架和最近报道的大肠杆菌染色体的高分辨率Hi-C数据，以开发出一个全面的大肠杆菌模型染色体以5 kg碱基对分辨率解析。该模型捕获由线性组织的遗传基因座和环状螺旋结构中分离的宏域组成的自组织染色体，没有净手性。此外，全基因组图谱可识别多个染色体相互作用域（CID），并与大肠杆菌染色体的以转录为中心的模型很好地相互佐证。研究进一步证明，尽管只有一小部分的Hi-C接触决定了潜在的染色体组织，但是没有Hi-C编码的接触信息的随机游走聚合物链将无法绘制出大肠杆菌特有的关键基因组相互作用。。总的来说，目前的工作与Hi-C相互作用相集成，阐明了细菌染色体在多个尺度上的组织，从识别粗粒度的螺旋状，宏域分离的形态到细粒度的CID表现。规模。