Microscopy data from: Identification of genetic interactions with priB links the PriA/PriB DNA replication restart pathway to double-strand DNA break repair in Escherichia coli

Collisions between DNA replication complexes (replisomes) and impediments
such as damaged DNA or proteins tightly bound to the chromosome lead to
premature dissociation of replisomes at least once per cell cycle in
Escherichia coli. Left unrepaired, these events produce incompletely
replicated chromosomes that cannot be properly partitioned into daughter
cells. DNA replication restart, the process that reloads replisomes at
prematurely terminated sites, is therefore essential in E. coli and other
bacteria. Three replication restart pathways have been identified in E.
coli: PriA/PriB, PriA/PriC, and PriC/Rep. A limited number of genetic
interactions between replication restart and other genome maintenance
pathways have been defined, but a systematic study placing replication
restart reactions in a broader cellular context has not been performed. We
have utilized transposon insertion sequencing to identify new genetic
interactions between DNA replication restart pathways and other cellular
systems. Known genetic interactors with the priB replication restart gene
(uniquely involved in the PriA/PriB pathway) were confirmed and several
novel priB interactions were discovered. Far fewer connections were found
with the PriA/PriC or PriC/Rep pathways, suggesting a primacy role for the
PriA/PriB pathway in E. coli. Targeted genetic and imaging-based
experiments with priB and its genetic partners revealed significant
double-strand DNA break (DSB) accumulation in strains with mutations in
dam, rep, rdgC, lexA, or polA. Modulating the activity of the RecA
recombinase partially suppressed the detrimental effects of rdgC or lexA
mutations in ΔpriB cells. Taken together, our results highlight roles for
several genes in DSB homeostasis and define a genetic network that
facilitates DNA repair/processing upstream of PriA/PriB-mediated DNA
replication restart in E. coli.