Interconnecting solvent quality, transcription, and chromosome folding in Escherichia coli.
Cell
; 184(14): 3626-3642.e14, 2021 07 08.
Article
in En
| MEDLINE
| ID: mdl-34186018
ABSTRACT
All cells fold their genomes, including bacterial cells, where the chromosome is compacted into a domain-organized meshwork called the nucleoid. How compaction and domain organization arise is not fully understood. Here, we describe a method to estimate the average mesh size of the nucleoid in Escherichia coli. Using nucleoid mesh size and DNA concentration estimates, we find that the cytoplasm behaves as a poor solvent for the chromosome when the cell is considered as a simple semidilute polymer solution. Monte Carlo simulations suggest that a poor solvent leads to chromosome compaction and DNA density heterogeneity (i.e., domain formation) at physiological DNA concentration. Fluorescence microscopy reveals that the heterogeneous DNA density negatively correlates with ribosome density within the nucleoid, consistent with cryoelectron tomography data. Drug experiments, together with past observations, suggest the hypothesis that RNAs contribute to the poor solvent effects, connecting chromosome compaction and domain formation to transcription and intracellular organization.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Solvents
/
Transcription, Genetic
/
Chromosomes, Bacterial
/
Escherichia coli
/
Nucleic Acid Conformation
Language:
En
Journal:
Cell
Year:
2021
Type:
Article
Affiliation country:
United States