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In vivo visualization of type II plasmid segregation: bacterial actin filaments pushing plasmids
- Source :
- The Journal of Cell Biology
- Publication Year :
- 2007
- Publisher :
- The Rockefeller University Press, 2007.
-
Abstract
- Type II par operons harness polymerization of the dynamically unstable actin-like protein ParM to segregate low-copy plasmids in rod-shaped bacteria. In this study, we use time-lapse fluorescence microscopy to follow plasmid dynamics and ParM assembly in Escherichia coli. Plasmids lacking a par operon undergo confined diffusion with a diffusion constant of 5 x 10(-5) microm(2)/s and a confinement radius of 0.28 microm. Single par-containing plasmids also move diffusively but with a larger diffusion constant (4 x 10(-4) microm(2)/s) and confinement radius (0.42 microm). ParM filaments are dynamically unstable in vivo and form spindles that link pairs of par-containing plasmids and drive them rapidly (3.1 microm/min) toward opposite poles of the cell. After reaching the poles, ParM filaments rapidly and completely depolymerize. After ParM disassembly, segregated plasmids resume diffusive motion, often encountering each other many times and undergoing multiple rounds of ParM-dependent segregation in a single cell cycle. We propose that in addition to driving segregation, the par operon enables plasmids to search space and find sister plasmids more effectively.
- Subjects :
- Operon
Biology
Microfilament
medicine.disease_cause
Models, Biological
Article
Chromosome segregation
Diffusion
03 medical and health sciences
Plasmid
Bacterial Proteins
Chromosome Segregation
medicine
Escherichia coli
Actin
Research Articles
030304 developmental biology
0303 health sciences
030306 microbiology
ParM
Cell Biology
Chromosomes, Bacterial
Actin cytoskeleton
Molecular biology
Actin Cytoskeleton
Biophysics
Plasmids
Subjects
Details
- Language :
- English
- ISSN :
- 15408140 and 00219525
- Volume :
- 179
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- The Journal of Cell Biology
- Accession number :
- edsair.doi.dedup.....b790900358e414a62d5291a04e9c618d