Fig.
9. YbeY overexpression partially rescues the delayed outgrowth inΔybeX mutant. (A ) A scheme of E. coli open
reading frame plasmid library selection experiment for the search of
compensatory plasmids rescuing the ΔybeX extended lag phase
phenotype. The selection involved sequential regrowth in 25 mL LB medium
containing 50 µg/mL Zeocin. Every 12 hours, a 1:100 culture sample was
transferred to a fresh LB and incubated for another 12 hours at 37°C
with aeration. (B ) Overexpression of YbeY from a pET-based
plasmid under the control of taq promoter in the presence of 1 mM IPTG
leads to shortened growth lag in the ΔybeX background.
(C ) YbeX overexpression from a single copy TransBac library
plasmid in the presence of 1mM IPTG has a profound negative effect on
the growth of the ΔybeY . The wild-type and ΔybeY strains
were conjugated with the backbone TransBac library plasmid (empty),ybeX or ybeY overexpressing single-copy plasmids. The
cells were grown in LB liquid medium with tetracycline and 1 mM IPTG.
(D-E ) ΔrimM and ΔyjeQ Keio mutant strains were
conjugated with the indicated TransBac library plasmids as in panel C.
The outgrowth from stationary phase cultures was monitored with aeration
in 96-well plates in LB medium at 37°C. The logistic curve fits
summarize three to four biological replicates, each comprising a minimum
of three technical replicates. Shaded areas represent 95% CI-s.