title: ParA-mediated plasmid partition driven by protein pattern self-organization.
abstract: DNA segregation ensures the stable inheritance of genetic material prior to cell division. Many bacterial chromosomes and low-copy plasmids, such as the plasmids P1 and F, employ a three-component system to partition replicated genomes: a partition site on the DNA target, typically called parS, a partition site binding protein, typically called ParB, and a Walker-type ATPase, typically called ParA, which also binds non-specific DNA. In vivo, the ParA family of ATPases forms dynamic patterns over the nucleoid, but how ATP-driven patterning is involved in partition is unknown. We reconstituted and visualized ParA-mediated plasmid partition inside a DNA-carpeted flowcell, which acts as an artificial nucleoid. ParA and ParB transiently bridged plasmid to the DNA carpet. ParB-stimulated ATP hydrolysis by ParA resulted in ParA disassembly from the bridging complex and from the surrounding DNA carpet, which led to plasmid detachment. Our results support a diffusion-ratchet model, where ParB on the plasmid chases and redistributes the ParA gradient on the nucleoid, which in turn mobilizes the plasmid.
authors: Laboratory of Molecular Biology, National Institute of Diabetes, and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0540, USA.
authors: Ling Chin
authors: LC
authors: Hwang
authors: Anthony G
authors: AG
authors: Vecchiarelli
authors: Yong-Woon
authors: YW
authors: Han
authors: Michiyo
authors: M
authors: Mizuuchi
authors: Yoshie
authors: Y
authors: Harada
authors: Barbara E
authors: BE
authors: Funnell
authors: Kiyoshi
authors: K
authors: Mizuuchi
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D017101:Bacteriophage P1 / Q000235:genetics* / Q000378:metabolism; D002455:Cell Division; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D005144:F Factor / Q000235:genetics* / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008954:Models, Biological; D011485:Protein Binding; D055503:Protein Multimerization; D059008:Time-Lapse Imaging; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; C121785:ParB protein, Enterobacteria phage P1; D014764:Viral Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases