文章基本信息

标题：Physical Modeling of a Sliding Clamp Mechanism for the Spreading of ParB at Short Genomic Distance from Bacterial Centromere Sites
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作者：Jean-Charles Walter ; Jérôme Rech ; Nils-Ole Walliser 等
期刊名称：iScience
印刷版ISSN：2589-0042
出版年度：2020
卷号：23
期号：12
页码：1-21
DOI：10.1016/j.isci.2020.101861
语种：English
出版社：Elsevier
摘要：SummaryBacterial ParB partitioning proteins involved in chromosomes and low-copy-number plasmid segregation are cytosine triphosphate (CTP)-dependent molecular switches. CTP-binding converts ParB dimers to DNA clamps, allowing unidimensional diffusion along the DNA. This sliding property has been proposed to explain the ParB spreading over large distances fromparScentromere sites where ParB is specifically loaded. We modeled such a “clamping and sliding” mechanism as a typical reaction-diffusion system, compared it to the F plasmid ParB DNA binding pattern, and found that it can account neither for the long range of ParB binding to DNA nor for the rapid assembly kinetics observedin vivoafterparSduplication. Also, it predicts a strong effect on the F plasmid ParB binding pattern from the presence of a roadblock that is not observed in ChIP-sequencing (ChIP-seq). We conclude that although “clamping and sliding” can occur at short distances fromparS, another mechanism must apply for ParB recruitment at larger genomic distances.Graphical AbstractDisplay OmittedHighlights•A physical model for ParB clamping and sliding onparS-proximal DNA is proposed•Clamped ParB sliding does not account for ParB binding at a large distance fromparS•Two distinct mechanisms must be at play for partition complex assemblyGene Process; Microbial Genetics; Systems Biology