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This content will become publicly available on February 19, 2026

Title: Chromosome segregation dynamics during the cell cycle of Staphylococcus aureus
Abstract Research on chromosome organization and cell cycle progression in spherical bacteria, particularlyStaphylococcus aureus, remains limited and fragmented. In this study, we established a working model to investigate chromosome dynamics inS. aureususing a Fluorescent Repressor-Operator System (FROS), which enabled precise localization of specific chromosomal loci. This approach revealed that theS. aureuscell cycle and chromosome replication cycle are not coupled, with cells exhibiting two segregated origins of replication at the start of the cell cycle. The chromosome has a specific origin-terminus-origin conformation, with origins localizing near the membrane, towards the tip of each hemisphere, or the “cell poles”. We further used this system to assess the role of various proteins with a role inS. aureuschromosome biology, focusing on the ParB-parSand SMC-ScpAB systems. Our results demonstrate that ParB binds fiveparSchromosomal sequences and the resulting complexes influence chromosome conformation, but play a minor role in chromosome compaction and segregation. In contrast, the SMC-ScpAB complex plays a key role inS. aureuschromosome biology, contributing to chromosome compaction, segregation and spatial organization. Additionally, we systematically assessed and compared the impact of proteins linking chromosome segregation to cell division—Noc, FtsK, SpoIIIE and XerC—on origin and terminus number and positioning. This work provides a comprehensive study of the factors governing chromosome dynamics and organization inS. aureus, contributing to our knowledge on chromosome biology of spherical bacteria.  more » « less
Award ID(s):
2022049
PAR ID:
10629062
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
bioRxiv
Date Published:
Format(s):
Medium: X
Institution:
bioRxiv
Sponsoring Org:
National Science Foundation
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