Generally, each molecule of plasmid diffuses randomly, so the probability of having a plasmid-less daughter cell is 21−N, where N is the number of copies.
Partition systems involve three elements, organized in an auto-regulated operon:[2] The centromere-like DNA site is required in cis for plasmid stability.
The NTPase uses energy from NTP binding and hydrolysis to directly or indirectly move and attach plasmids to specific host location (e.g. opposite bacterial cell poles).
The centromere like site, parC contains two sets of five 11 base pair direct repeats separated by the parMR promoter.
[7][22] The mechanism of partition involved here is a pushing mechanism:[23] The filament of ParM is regulated by the polymerization allowed by the presence the partition complex (ParR-parC), and by the depolymerization controlled by the ATPase activity of ParM.
[25] The StbA-stbDRs complex may be used to pair plasmid the host chromosome, using indirectly the bacterial partitioning system.
This system represents the first evidence for a mechanistic interplay between plasmid segregation and conjugation processes.
This gene does not effect the plasmid copy number nor the grow rate (excluding its implication in a post-segregational killing system).