Cloning, homology modeling, heterologous expression and bioinformatic analysis of Ure2pA glutathione S-transferase gene from white rot fungus Trametes gibbosa

Glutathione S-transferases (GSTs) are a class of enzymes with detoxification function. GSTs can be used for the degradation of toxic aromatic compounds, such as dyes. In order to promote their application and cost-effective dye degradation and to understand their structure and function more deeply, we cloned and expressed a gst2 gene from Trametes gibbosa-a white rot fungus. T.gibbosa gst2 has a 672-bp open reading frame (ORF) and encodes 223 amino acids. The recombinant Tg-gst2 in Escherichia coli has a molecular weight of 25.59 k. Real-time polymerase chain reaction and high throughput sequencing technique were used to verify Tg-gst2 gene response to congo red dye. GST activity enhanced with congo red treatment. The tertiary structure of Tg-GST2 was predicted using homology modeling, and we found that it belongs to Ure2pA family of GST, which is a specific family of fungi. Active sites contained catalytic tri-linked groups, such as Gly15-Pro16-Asn17. Oxidized glutathione binding residues are Gln 44, Arg 57, Ile 58, Glu 73, Ser 74, Ser 111, Arg 137 and Trp 174. Molecular docking predicted that the binding effect of Tg-GST2 with oxidized glutathione and congo red was strong. This study has great significance in the research and application GST of Ure2pA family in dye decolorization and detoxification. Supplemental data for this article is available online at https://doi.org/10.1080/13102818.2021.1997157 .