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 |
Thermochaetoides dissita |