Structural comparison of TvGSTO3S and −6S isoforms showing differences between H-sites and L-sites. The structures shown are TvGSTO3S in complex with 2,4-HBP (top left) and TvGSTO6S in complex with naringenin (top right). In both cases, helix α9 and C-terminal tail were removed from structures for clarity. Monomers A and B are colored white and grey, respectively. 2,4-HBP and naringenin molecules are represented as yellow sticks. H-site and L-sites residues are colored respectively cyan and grey in the structures (highlighted respectively cyan and grey on the structural alignment). G-site residues are highlighted green in the sequences and are not shown on structures for clarity. Catalytic serine is highlighted yellow in the sequences. Secondary structures are labelled and shown using arrows (β-strands) and squiggles (helices). Secondary structure elements are based on TvGSTO6S. Helix α9 extra turns in TvGSTO6S are colored red on the sequence alignment.