Genetic mapping of katF, a locus that with katE affects the synthesis of a second catalase species in Escherichia coli

Abstract

A class of catalase-deficient mutants that was unlinked to katE was localized between mutS and cys at 59.0 min on the Escherichia coli genome. This locus was named katF. Transposon Tn10 insertions were isolated that mapped in both katE and katF loci. The catalase species present in katE+ and katF+ recombinants was found to be different from the main catalase activities, HPI and HPII, in several respects. It did not have an associated peroxidase activity; it was electrophoretically slower on native polyacrylamide gels; it eluted from DEAE-Sephadex A50 at a higher salt concentration; its Km for H2O2 was 30.9 mM as compared with 3.7 mM for HPI and HPII; its synthesis was not induced by ascorbate; and it did not cross react with HPI-HPII antisera. This new catalase was labeled HPIII.