Using transposon mutagenesis to characterise the gene of unknown function yhcB

yhcB is a conserved gene of unknown function that contributes to envelope stability in Escherichia coli. Here, we constructed two dense transposon mutant libraries in E. coli BW25113 and a BW25113-yhcB gene-deletion strain to identify the genetic interaction network of yhcB. We identified 87 genes that are synthetically lethal with yhcB, and 76 genes that contribute to fitness in this background. We also exposed the yhcB-transposon library to two envelope stress conditions, vancomycin and SDS+EDTA, to identify mutations that restore viability of the parent yhcB-deletion strain. Together these data reveal the genetic interaction network of yhcB under normal conditions of growth and under conditions of envelope stress. Lastly, we exposed the yhcB-deletion strain to vancomycin and recovered 6 natural revertant suppressor mutants. The complementary screening method revealed restorative mutations that could not be identified in a transposon mutagenesis screen.Altogether, these data confirm a role for yhcB in maintaining envelope stability.