Wang, X.-T.; Ma, B.-G.

The spatial organization of bacterial chromosomes is crucial for cellular functions. It remains unclear how bacterial chromosomes adapt to high temperature stress. This study delves into the 3D genome architecture and transcriptomic responses of Escherichia coli under heat stress condition to unravel the intricate interplay between chromosome structure and environmental cues. By examining the role of macrodomains, chromosome interaction domains (CIDs), and nucleoid-associated proteins (NAPs), this work unveils the dynamic changes in chromosome conformation and gene expression patterns induced by high temperature stress. It was observed that under heat stress, short-range interaction frequency of chromosome decreased, while the long-range interaction frequency of the Ter macrodomain increased. Furthermore, two metrics, namely, Global Compactness (GC) and Local Compactness (LC), were devised to measure and compare the compactness of chromosomes based on their 3D structure models. The findings in this work shed light on the molecular mechanisms underlying thermal adaptation and chromosomal organization in bacterial cells, offering valuable insights into the complex interrelationships between environmental stimuli and genomic responses.