Abstract:
Abstract
Catalase (EC 1.11.1.6; CAT) is a ubiquitous enzyme present in plants, animals, and
microorganisms that catalyzes the breakdown of hydrogen peroxide into water and oxygen.
Detailed information on catalases in fungal species is limited. The current study is based on
genome-wide analysis of catalases from five fungal sources (Aspergillus flavus, Aspergillus
fumigatus, Aspergillus oryzae, Saccharomyces cerevisiae, Neurospora crassa). A total of 21
protein sequences were identified in the BLASTp search having catalase domain. The conserved
amino acid residue with catalase domain were present in all sequences. The phylogeny revealed
close relationship of Aspergillus oryzae with Aspergillus flavus. The Phenogram plot indicated the
catalase genes were found on chromosome number 2,3,4,5,6 and 7. Gene structure analysis
predicted the diverse range intron-exon. The analysis also revealed that only ScCAT1 and ScCAT2
were found intronless. Motif analysis showed motifs 1-9 were present in all sequences except motif
10. Subcellular localization in different compartments revealed that mostly present in peroxisomes,
mitochondria and cytoplasmic regions. Physicochemical properties revealed that their pI ranged
from 5-7. The instability index showed a value is <40 which directs the stable nature of proteins.
In 3D structure prediction, 5 best models were selected. AfuCAT1 was predicted to be the top
among the best models. Gene expression analysis of catalases in Aspergillusoryzae revealed that
only two genes AorCAT4 and AorCAT6 downregulated in control conditionsand the same two
genes upregulated in stress conditions. Genome-wide analysis of catalases givesinformation about
beneficial features, characteristics and structure of catalases which would be helpful in invitro
experimentations for industrial application.
