Abstract
The catalase enzyme is present widely in all living organisms. It is the key enzyme in terms of signaling and the metabolism of hydrogen peroxide and belongs to a large superfamily. The main reason to study evolution is the great role of catalase in the degradation of hydrogen peroxide as it is very necessary for all aerobic eukaryotes and prokaryotes. It has great importance due to its linkage with cancer and aging. The sequences of catalase enzymes are present in a wide range of public databases. For the assessment of phylogeny of catalase sequences, 45 full-length amino acid sequences of catalase were searched and collected for further study. The sequences were used for multiple sequence alignment, phylogenetic construction, motif discovery, domain identification, and discovering individual amino acid composition. MSA revealed amino acid glycine and aspartic acid play an important role in the evolution from prokaryotic to eukaryotic organisms with concern for catalase. Two main sequence clusters were obtained by phylogenetic analysis. One cluster comprised of 15 plant species, 8 bacterial species, and 3 fungal species. Cluster II contained 7 bacterial species and 12 fungal species. All the observed organisms showed similar domain structures but some fungal and bacterial sequences possessed the c-terminal domains. The average amino acid frequency was 7.35% that was very much high in contrast to other amino acids. This idea about amino acid frequencies demonstrated that alanine played a vital role in the composition of catalase.