author(s)
Ajit Tiwari, AD Upadhyay, Himanshu Priyadarshi, Rumpi Ghosh and Suresh Yambem

abstract
Iron excess in form of ferrous (Fe2+) in soil and water is one of the major issues in aquaculture in Tripura state of India. Excess iron in water causes iron toxicity in fishes, so it becomes important to identify the structural and functional role of iron related protein in fish species. Ferritin heavy chain subunit has di-Fe binding site in fourth helix that interacts with oxygen and is responsible for ferroxidase activity in fishes. In present study, structural and functional property of ferritin heavy chain protein in fishes was analyzed. The structural and functional analyses of ferritin in the fish species belonging to different orders were performed on Expasy Prot Param, GOR IV, Swiss Model, and STRING 10.0. Physicochemical characterization of ferritin heavy chain subunit of freshwater fishes reveals that the protein is acidic, unstable and hydrophilic with maximum percentage of alpha helix followed by random coil and extended strand. The tertiary structure of ferritin heavy chain subunit was predicted by the Swiss Model and verified by Ramachandran plot. In protein-protein interaction analysis via STRING 10.0 tool, 10 enriched pathways of KEGG, 15 UNIPROT, 13 PFAM Domains common to Inter Pro Scan and 7 SMART Protein Domains were identified in 35 species of freshwater fish.