AI Article Synopsis
- Chromosome segregation in Caulobacter crescentus is a quick process, but the exact mechanisms behind it are still not fully understood.
- The study identifies that chromosomal movements hinge on the parS site, which is crucial for segregation initiation, and that this site exerts force regardless of its position on the chromosome.
- Segregation cannot start until parS is replicated, and mutations affecting the ParA protein can stop segregation without impacting the start of replication.
Article Abstract
Chromosome segregation in bacteria is rapid and directed, but the mechanisms responsible for this movement are still unclear. We show that Caulobacter crescentus makes use of and requires a dedicated mechanism to initiate chromosome segregation. Caulobacter has a single circular chromosome whose origin of replication is positioned at one cell pole. Upon initiation of replication, an 8-kb region of the chromosome containing both the origin and parS moves rapidly to the opposite pole. This movement requires the highly conserved ParABS locus that is essential in Caulobacter. We use chromosomal inversions and in vivo time-lapse imaging to show that parS is the Caulobacter site of force exertion, independent of its position in the chromosome. When parS is moved farther from the origin, the cell waits for parS to be replicated before segregation can begin. Also, a mutation in the ATPase domain of ParA halts segregation without affecting replication initiation. Chromosome segregation in Caulobacter cannot occur unless a dedicated parS guiding mechanism initiates movement.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2563096 | PMC |
| http://dx.doi.org/10.1073/pnas.0807448105 | DOI Listing |
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