Movement and equipositioning of plasmids by ParA filament disassembly
Name
Ringgaard-2009-Movement and equipos.pdf
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2.43 MB
Format
Adobe PDF
Checksum (MD5)
0598131d25a668e66f5bd52e0018c0d7
Author(s)
Ringgaard, Simon
van Zon, Jeroen Sebastiaan
Howard, Martin
Gerdes, Kenn
Date Issued
November 2009
Journal
Proceedings of the National Academy of Sciences of the United States of America
Publisher
National Academy of Sciences
Citation
Ringaard, van Zon, Howard, and Gerdes (2009). Movement and equipositioning of plasmids by ParA filament disassembly. Proceedings of the National Academy of Sciences of the United States of America 106:19369-19374. Copyright ©2009 by the National Academy of Sciences
Version
Final published version
Abstract
Bacterial plasmids encode partitioning (par) loci that confer stable plasmid inheritance. We showed previously that, in the presence of ParB and parC encoded by the par2 locus of plasmid pB171, ParA formed cytoskeletal-like structures that dynamically relocated over the nucleoid. Simultaneously, the par2 locus distributed plasmids regularly over the nucleoid. We show here that the dynamic ParA patterns are not simple oscillations. Rather, ParA nucleates and polymerizes in between plasmids. When a ParA assembly reaches a plasmid, the assembly reaction reverses into disassembly. Strikingly, plasmids consistently migrate behind disassembling ParA cytoskeletal structures, suggesting that ParA filaments pull plasmids by depolymerization. The perpetual cycles of ParA assembly and disassembly result in continuous relocation of plasmids, which, on time averaging, results in equidistribution of the plasmids. Mathematical modeling of ParA and plasmid dynamics support these interpretations. Mutational analysis supports a molecular mechanism in which the ParB/parC complex controls ParA filament depolymerization.
Subjects
cytoskeleton
DNA segregation
mathematical modeling
pulling
ParA ParB
MIT Department
Massachusetts Institute of Technology. Department of Physics
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1073/pnas.0908347106
