EC Number   |
General Information |
Reference |
|---|
    1.11.1.21 | evolution |
catalase-peroxidases (KatGs) are a superfamily of reactive oxygen species (ROS)-degrading enzymes believed to have been horizontally acquired by ancient Ascomycota from bacteria. Subsequent gene duplication resulted in two KatG paralogues in ascomycetes: the widely distributed intracellular KatG1 group and the phytopathogen-dominated extracellular KatG2 group |
-, 765406 |
| 1.11.1.21 | evolution |
catalase-peroxidases represent one important subfamily of ancestral antioxidant enzymes originally evolved in bacteria for the protection against various forms of oxidative stress. KatG genes coding for these bifunctional catalase-peroxidases were during their peculiar evolution transferred from Bacteroidetes to the fungal phylum Ascomycota via a horizontal gene transfer event. Identification of the gene for thermostable bifunctional catalase-peroxidases in Chaetomium thermophilum and their molecular evolution, overview. The gene from Chaetomium thermophilum, CthediskatG, resembling its bacterial counterparts has a typical eukaryotic transcription start site and also contains a conserved eukaryotic polyadenylation signal behind its 3' terminus. PolyA tails are detected in corresponding transcripts of katG from two different mRNA libraries of Chaetomium thermophilum thermophilum var. disstum. Although otherwise highly conserved, a unique 60 bp long deletion leading in the translated product with high probability to a modified loop and thus access to the prosthetic heme group is observed in katG genes of only two Chaetomium thermophilum variants. Molecular phylogeny revealing the evolutionary position of fungal thermostable catalase-peroxidases within a robust phylogenetic tree of the whole KatG subfamily, overview. Molecular phylogeny and phylogenetic tree |
764806 |
| 1.11.1.21 | malfunction |
a knockout mutation in katG that causes loss of catalase-peroxidase activity correlates with increased susceptibility to H2O2 and a superoxide generator and is avirulent in a plant model system. The katG mutant shows a 10fold increase in resistance to tert-butyl hydroperoxide compared with the wild type strain |
715357 |
| 1.11.1.21 | malfunction |
although the rate of H2O2 decomposition is about 30times lower in the katG deletion mutant than in the wild type, the strain has a normal phenotype and its doubling time as well as its resistance to H2O2 and methyl viologen are indistinguishable from those of the wild type |
715337 |
| 1.11.1.21 | malfunction |
catalase-peroxidase activity is decreased in a Caulobacter crescentus rho::TN5 mutant |
715053 |
| 1.11.1.21 | malfunction |
detection of a unique deletion in CthediskatG gene leads to a shortened large loop 1 that can have an impact on a modified accessibility to the heme active site from the protein surface and overall stability of this enzyme |
764806 |
| 1.11.1.21 | malfunction |
mutation at position 315 in the katG gene, encoding the catalase-peroxidase (KatG) enzyme, is the major cause of isoniazid (INH) resistance in Mycobacterium tuberculosis. INH resistance is regarded as a major impediment to the tuberculosis (TB) control programme and contributes to the emergence of multidrug-resistant strains. Analysis of the molecular mechanisms of INH resistance, overview. The five KatG mutations, S315T, S315I, S315R, S315N and S315G , affect enzyme activity in different ways, which can be attributed to conformational changes in mutant KatG that result in altered binding affinity to INH and eventually to INH resistance, docking study. Analysis of molecular dynamics (MD) experiments suggest that fluctuations and deviations are higher at the INH binding residues for the mutants than for the wild-type. Reduction in the hydrogen bond network after MD in all KatG enzymes implies an increase in the flexibility and stability of protein structures. Since KatG is a conjugated protein, docking is first done with heme, and then it is further docked with INH |
-, 765180 |
| 1.11.1.21 | malfunction |
mutations of the katG gene in Mycobacterium tuberculosis (T354I, G421S, R463L, and V721M) are a major INH resistance mechanism. The Mycobacterium tuberculosis clinical isolate R2 shows INH resistance at a high level of 0.01 mg/ml |
-, 765229 |
| 1.11.1.21 | malfunction |
mutations that render the enzyme unable to activate the pro-drug lead to isoniazid (INH) resistance. For two INH resistance variants, W107R and T275P, significant structural disorder relating to heme uptake and retention is the likely cause for INH resistance, dynamics of heme binding are determined by cryo-electronmicroscopy of wild-type and mutant enzymes at 2.7-3.7 A resolution, overview |
-, 765846 |
| 1.11.1.21 | malfunction |
Mycobacterium tuberculosis isolates with defects in the kutG gene encoding a catalase-peroxidase enzyme exhibit resistance to isoniazid |
714115 |
