Figure 1.
Colony catalase activity assay.
E. faecalis OG1RF (wild-type) and EMB1 (katA::ISS1) colonies grown on TH agar plates with and without 8 µM hemin added and zymogram stained for catalase activity.
Figure 2.
Distribution of transposon insertion sites.
Transposon insertion sites in the OG1RF genome of 42 catalase-deficient mutants isolated in this work are shown. The strain names (EMBx) are indicated and ISS1-derived mutants are marked with an asterisk.
Figure 3.
Genomic context of loci for which two or more independent catalase-deficient transposon insertion mutants were obtained.
Insertion sites in the E. faecalis OG1RF chromosome are marked with the designation of the respective isolate (EMBx) and ISS1-derived mutants are marked with an asterisk. See Table 1.
Table 1.
Loci for which two or more independent catalase-deficient transposon insertion mutants were obtained.
Table 2.
Bacterial strains.
Figure 4.
Difference (dithionite-reduced minus air-oxidized) absorption spectra of cytoplasmic membranes isolated from strain OG1RF (A) and EMB4 (B) grown in the presence of hemin. The spectrum of strain EMB44 was similar to that of EMB4. The absorbance scale is indicated by the vertical bar.
Figure 5.
Sequence alignment of catalase polypeptides.
Multiple amino acid sequence alignment of six catalases showing conserved residues in the N-terminal arm. Human and bovine catalase enzymes have an extended N-terminal region containing an additional α-helix. Residues Pro28 (mutated to a Thr in strain EMB4) and the essential His54 (proximal to heme iron) in E. faecalis KatA are indicated by arrows. E. faecalis (UniProt F2MTL2), B. subtilis (P26901), Bos taurus (P00432), Homo sapiens (P04040), Lactobacillus sakei (P30265), Saccharomyces cerevisiae (P15202), Candida tropicalis (P07820).