Phylogenetic tree of cyanobacterial glutathione S-transferase (GST) sequences belonging to the five orders. Cyanobacterial GSTs were clustered in 10 clades consisting of 12 GST classes. Mega5 software were used to construct the tree using maximum likelihood statistical method with 500 replicates bootstrap. The substitution model used was Jones–Taylor–Thornton method using the rates and pattern as Gamma Distributed (G). The constructed trees were visualized and analysed using FigTree v1.3. Each clade was analysed manually, named and colour codes were given to separate each clade which represents a type of GST. Chi, cyGSTChi; X1, cyGSTX1; X2, cyGSTX2; X3, cyGSTX3; X4, cyGSTX4; X5, cyGSTX5; X6, cyGSTX6; X7, cyGSTX7; X8, cyGSTX8; X9, cyGSTX9; X10, cyGSTX10; and X11, cyGSTX11.