Reconstitution of DNA segregation driven by assembly of a prokaryotic actin homolog.
Multiple unrelated polymer systems have evolved to partition DNA molecules between daughter cells at division. To better understand polymer-driven DNA segregation, we reconstituted the three-component segregation system of the R1 plasmid from purified components. We found that the ParR/parC complex can construct a simple bipolar spindle by binding the ends of ParM filaments, inhibiting dynamic instability, and acting as a ratchet permitting incorporation of new monomers and riding on the elongating filament ends. Under steady-state conditions, the dynamic instability of unattached ParM filaments provides the energy required to drive DNA segregation.
Garner
Ethan C
EC
Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA.
Campbell
Christopher S
CS
Weibel
Douglas B
DB
Mullins
R Dyche
RD
D000199:Actins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D001704:Biopolymers; D027101:DNA Topoisomerase IV / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D008863:Microspheres; D011485:Protein Binding; D011815:R Factors / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism
D000199:Actins; D001426:Bacterial Proteins; D001704:Biopolymers; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C471255:ParM protein, E coli; C086169:ParR protein, bacteria; D012097:Repressor Proteins; D000255:Adenosine Triphosphate; D027101:DNA Topoisomerase IV