Fig. 4.

PrpA controls plasmid copy number. (A) PrpT/PrpA TA system does not control the segregational stability of plasmid pMBL6842. The wild-type and deletion mutants were cultured in 2216E medium without antibiotic for 448 generations. Quantification of plasmid copy number after cultivation for 6 h (in the exponential phase) and 24 h (in the late stationary phase) from the starting point OD₆₀₀ ∼0.01, by qPCR (n = 4) (B) and by PCR-free whole-genome sequencing (C). (D) Quantification of the plasmid copy number when expressing prpA and prpAT under their native promoter in the ΔprpAT strain after 24 h by qPCR (n = 4).