Figure 7.

trmB exerts effects on catalases. (A) Total catalase activities of the wild type, trmB mutant, and complemented strains upon exposure to H₂O₂. (B) Comparison of KatA activities of the wild type and trmB mutant strains. KatA activity was examined by a catalase gel activity assay. The colorless band indicates the area where H₂O₂ was decomposed; M indicates the protein molecular weight markers. (C) Western blot analysis of OxyR, KatA and KatB proteins. OxyR and KatA levels were assessed using anti-OxyR and anti-KatA antibodies, respectively. The amount of KatB protein overexpressed from the pBB-katB-6XHis plasmid was assessed using anti-6X-His antibody. The amount of total protein loaded in each gel was shown as loading control. (D) Relative expression levels of katA, katB, katB-His, and oxyR in the wild type and trmB mutant strains upon H₂O₂ exposure. Data represent the mean ± SD for three biological replicates for (A) and for five biological replicates for (D). Asterisks denote a significant difference by t-test (* P ≤ 0.05, ** P ≤ 0.01).