Homology modeling and functional sites prediction of azoreductase enzyme from the cyanobacterium Nostoc sp. PCC7120

Abstract

Industrial dyes such as azodyes are potential environmental pollutants causing deleterious health hazards complications. These dyes are potentially degraded by azoreductase enzyme which is widely distributed in bacteria and also cyanobacteria. The azoreductase enzymes from cyanobacteria have not been explored in detail. Hence this enzyme from Nostoc sp. PCC 7120 has been addressed in detail in the present study considering to explore the physico-chemical properties, evolutionary relationships, functional sites and structural properties using various bioinformatics tools. Four conserved regions were obtained from the multiple sequence analysis. The multiple sequence alignment showed conserved regions at different stretches from 1-11, 40-57, 82-120 and 161-177 amino acid residues. These regions could be used for designing degenerate primers or probes for PCR-based amplification or hybridization-based detection of azoreductase sequences from different source organisms. Domain analysis and functional site prediction showed the presence of functional sites and domain such as flavodoxin like fold responsible for enzyme activity. 3D model was constructed and the best model was selected and validated. Superimposition of the final structure and the template showed variations in certain regions which might be involved in the accommodation of various dyes. Our results may be helpful for further investigations like docking studies as well as in vivo and in vitro conditions although these predictions still need to be studied.

An Integrative Approach to Study Bacterial Enzymatic Degradation of Toxic Dyes

“…Based on multiple sequences analysis, conserved regions were observed, considered an active site for interactions with dyes. These reasons are from 1 to 11, 40-57, 82-120, and 161-177 amino acid residues of azoreductase (Devi and Adhikari, 2012). It is very important to know the exact mechanism of dyes' interaction with bacterial enzymes, and in silico docking studies are beneficial to understand the mechanism behind it.…”