Figure 2.

The identification of active residues in MazF-at for ribonuclease activity. (a) Sequence alignments between MazF-at and MazF-ec. Residues were shaded according to BLOSUM62 score. Dark- and grey- shaded residues represent identical and similar amino acid residues, respectively; (b) Toxicity of MazF-at mutants, MazF-at-E24N, -E24Q, -E24K, -E24D, and -E24A, on plates. The cells of E. coli BW25113 harboring each mazE-at mutant in pBAD24 were incubated on the M9 plate with or without 0.2% L-arabinose; (c) Effect of MazF-at mutants, MazF-at-E24N, -E24Q, -E24K, -E24D, and -E24A induction on cell growth. The culture of E. coli BW25113 harboring each mazE-at mutant in pBAD24 was grown until the OD_600nm of the culture reached ~0.4, followed by adding 0.2% L-arabinose at 0 min, and bacterial growth was measured for 6 h at OD₆₀₀ nm. Error bars represent standard error of the mean (SEM).