title: Prokaryotic DNA segregation by an actin-like filament.
abstract: The mechanisms responsible for prokaryotic DNA segregation are largely unknown. The partitioning locus (par) encoded by the Escherichia coli plasmid R1 actively segregates its replicon to daughter cells. We show here that the ParM ATPase encoded by par forms dynamic actin-like filaments with properties expected for a force-generating protein. Filament formation depended on the other components encoded by par, ParR and the centromere-like parC region to which ParR binds. Mutants defective in ParM ATPase exhibited hyperfilamentation and did not support plasmid partitioning. ParM polymerization was ATP dependent, and depolymerization of ParM filaments required nucleotide hydrolysis. Our in vivo and in vitro results indicate that ParM polymerization generates the force required for directional movement of plasmids to opposite cell poles and that the ParR-parC complex functions as a nucleation point for ParM polymerization. Hence, we provide evidence for a simple prokaryotic analogue of the eukaryotic mitotic spindle apparatus.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Møller-Jensen
authors.forename: Rasmus Bugge
authors.initials: RB
authors.lastname: Jensen
authors.forename: Jan
authors.initials: J
authors.lastname: Löwe
authors.forename: Kenn
authors.initials: K
authors.lastname: Gerdes
mesh_terms: D000199:Actins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism; D027101:DNA Topoisomerase IV / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D011108:Polymers; D012097:Repressor Proteins / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D000199:Actins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C086169:ParR protein, bacteria; D011108:Polymers; D012097:Repressor Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D027101:DNA Topoisomerase IV; D008274:Magnesium