Figure 1.

ZorO and the role of negatively charged residues in ZorO mediated toxicity. ZorO sequence and its alpha helical structure predicted by Phyre 2.0 (A). Growth curve of E. coli UTK007 cells harboring indicated pAZ3 plasmid with ZorO or its variants under an arabinose inducible promoter (P_BAD). Arrows indicated time of arabinose addition (except for the uninduced control). (B) Control; (C) aspartate at position 2 converted to lysine (D2K); (D) aspartate at position 2 converted to asparagine (D2N); (E) aspartate at position 26 converted either to asparagine (D26N) or lysine (D26K); (F) glutamate at position 16 converted to arginine (E16R); (G) glutamate at position 16 converted to glutamine (E16Q). n = 3, shown are mean ± standard deviation. Multiple unpaired t test was performed computing variance for each comparison after arabinose induction. Adjusted p-values; ns > 0.05, ** p < 0.01, *** p < 0.001.