Regular cellular distribution of plasmids by oscillating and filament-forming ParA ATPase of plasmid pB171.
Centromere-like loci from bacteria segregate plasmids to progeny cells before cell division. The ParA ATPase (a MinD homologue) of the par2 locus from plasmid pB171 forms oscillating helical structures over the nucleoid. Here we show that par2 distributes plasmid foci regularly along the length of the cell even in cells with many plasmids. In vitro, ParA binds ATP and ADP and has a cooperative ATPase activity. Moreover, ParA forms ATP-dependent filaments and cables, suggesting that ParA can provide the mechanical force for the observed regular distribution of plasmids. ParA and ParB interact with each other in a bacterial two-hybrid assay but do not interact with FtsZ, eight other essential cell division proteins or MreB actin. Based on these observations, we propose a simple model for how oscillating ParA filaments can mediate regular cellular distribution of plasmids. The model functions without the involvement of partition-specific host cell receptors and is thus consistent with the striking observation that partition loci can function in heterologous host organisms.
Ebersbach
Gitte
G
Department of Biochemistry and Molecular Biology, Campusvej 55, DK-5230 Odense M, University of Southern Denmark, Denmark.
Ringgaard
Simon
S
Møller-Jensen
Jakob
J
Wang
Qing
Q
Sherratt
David J
DJ
Gerdes
Kenn
K
D000251:Adenosine Triphosphatases / Q000032:analysis / Q000378:metabolism*; D002503:Centromere / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000378:metabolism; D010957:Plasmids / Q000032:analysis / Q000378:metabolism*
D029968:Escherichia coli Proteins; C078473:MreB protein, E coli; D000251:Adenosine Triphosphatases