Fig 4. Construction of a transposon library in a yhcB mutant and identification of genes with a synthetic lethal relationship with yhcB.

(A) The ΔyhcB transposon library. A genome map of BW25113 starting at the annotation origin with the sense and antisense coding sequences of BW25113 shown in blue, respectively, and the position and frequency of sequenced transposon insertion events shown in pink. (B) Comparison of genes identified by bimodal analysis as significantly underrepresented by transposon mutants in each library. (C) The insertion profile of rodZ in the ΔyhcB library, with RodZ domains shown below in blue. (D) The log₂ fold-change of read depth per gene between the parent BW25113 and the ΔyhcB transposon library. Genes enriched for transposon insertions (>2-fold) in the yhcB library are shown in blue, indicative of more fit mutants. Genes with a >2-fold decrease in insertions are shown in red, indicative of sick mutants. A Q-value threshold of 0.01 was used (red horizontal line) (E) Comparison of genes predicted to be essential (sparsely disrupted genes) with genes identified as having a >2-fold decrease in reads compared to the control library (genes that contribute to fitness). This is a comparison of the bi-modal and enrichment analyses outputs. The overlap of these analyses are the 87 identified synthetic lethal genes (pink). Abbreviations: wild-type (WT); transmembrane domain (TM); helix-turn-helix domain (HTH).