TABLE 5.

Catalase activity of wild-type and mutant KatG, KatG-mediated INH-converting activity, and INH susceptibility

Recombinant KatGaCatalase activityKatG-mediated INH-converting activitybINH susceptibilityc
kcat (S−1)Km (mM)kcat/Km ratio (mutant/wild type)
Wild type2,403 ± 44060.1 ± 9.51.00+S
A245V*2,666 ± 53062.8 ± 10.81.06+S
Q295P*NDdNDNAeR
G297V*188 ± 3668.7 ± 7.00.07R
T324P*NDNDNAR
L48Q*-R463L1,776 ± 31064.8 ± 12.50.69+R
L141F*-R463LNDNDNAR
R463L2543 ± 45064.0 ± 11.01.01+S
L390 (CTA) insertion*NDNDNAR
  • a *, novel mutation.

  • b Time courses of net KatG-mediated INH conversion are shown in Fig. 2C.

  • c INH susceptibilities shown are those of M. tuberculosis H37Rv strains having the katG gene of the wild type and those of clinical strains having the katG gene with the respective mutation(s). S, susceptible; R, resistant.

  • d ND, not detected.

  • e NA, not applicable.