Key Laboratory of Synthetic Biology, Key Laboratory of Plant Design, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
Nat Commun. 2024 Sep 27;15(1):8283. doi: 10.1038/s41467-024-52484-2.
The nucleosome is one of the hallmarks of eukaryotes, a dynamic platform that supports many critical functions in eukaryotic cells. Here, we engineer the in vivo assembly of the nucleosome core in the model bacterium Escherichia coli. We show that bacterial chromosome DNA and eukaryotic histones can assemble in vivo to form nucleosome complexes with many features resembling those found in eukaryotes. The formation of nucleosomes in E. coli was visualized with atomic force microscopy and using tripartite split green fluorescent protein. Under a condition that moderate histones expression was induced at 1 µM IPTG, the nucleosome-forming bacterium is viable and has sustained growth for at least 110 divisions in longer-term growth experiments. It exhibits stable nucleosome formation, a consistent transcriptome across passages, and reduced growth fitness under stress conditions. In particular, the nucleosome arrays in E. coli genic regions have profiles resembling those in eukaryotic cells. The observed compatibility between the eukaryotic nucleosome and the bacterial chromosome machinery may reflect a prerequisite for bacteria-archaea union, providing insight into eukaryogenesis and the origin of the nucleosome.
核小体是真核生物的特征之一，是一种支持真核细胞许多关键功能的动态平台。在这里，我们在模式细菌大肠杆菌中设计了核小体核心的体内组装。我们表明，细菌染色体 DNA 和真核组蛋白可以在体内组装，形成具有许多与真核生物相似特征的核小体复合物。使用原子力显微镜和三部分分裂绿色荧光蛋白可视化了大肠杆菌中的核小体形成。在诱导 IPTG 浓度为 1μM 的情况下适度表达组蛋白的条件下，形成核小体的细菌是有活力的，并且在长期生长实验中至少进行了 110 次分裂的持续生长。它表现出稳定的核小体形成、整个传代过程中的一致转录组，以及在应激条件下的生长适应性降低。特别是，大肠杆菌基因区域中的核小体阵列具有类似于真核细胞的特征。观察到的真核核小体与细菌染色体机制之间的兼容性可能反映了细菌-古菌联合的先决条件，为真核生物的起源和核小体的起源提供了深入的了解。
