ParAB-mediated intermolecular association of plasmid P1 parS sites.
The P1 plasmid partition system depends on ParA-ParB proteins acting on centromere-like parS sites for a faithful plasmid segregation during the Escherichia coli cell cycle. In vivo we placed parS into host E. coli chromosome and on a Sop(+) F plasmid and found that the stability of a P1 plasmid deleted for parA-parB could be partially restored when parB was expressed in trans. In vitro, parS, conjugated to magnetic beads could capture free parS DNA fragment in presence of ParB. In vitro, ParA stimulated ParB-mediated association of intermolecular parS sites in an ATP-dependent manner. However, in the presence of ADP, ParA reduced ParB-mediated pairing to levels below that seen by ParB alone. ParB of P1 pairs the parS sites of plasmids in vivo and fragments in vitro. Our findings support a model whereby ParB complexes P1 plasmids, ParA-ATP stimulates this interaction and ParA-ADP inhibits ParB pairing activity in a parS-independent manner.
School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Tranum
T
Kaur
Qusai
Q
Al Abdallah
Nafiseh
N
Nafissi
Shawn
S
Wettig
Barbara E
BE
Funnell
Roderick A
RA
Slavcev
D000244:Adenosine Diphosphate; D001665:Binding Sites; D002453:Cell Cycle; D002503:Centromere; D019915:DNA Primase; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics*; D017384:Sequence Deletion
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C541712:ParA protein, E coli; D000244:Adenosine Diphosphate; D019915:DNA Primase; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C121791:dnaG protein, E coli