Fig. 4.

Recombinant mutant SULTs were constructed. A. Crystal structure of OXA-bound SmSULT (light orange): F39Y, L148I, T157S, F39Y/L149I, F39Y/T157S, F39Y/L149I/T157S; OXA-bound ShSULT (light blue): Y45F, I158L, S166T, Y54F/I158L. B. Crystal structure of substrate-free SjSULT with OXA (light orange) modeled in the binding pocket using coordinates from the OXA-bound SmSULT crystal structure. The V139 side chain of SjSULT creates a steric clash with OXA (light orange sphere). SjSULT is shown in the same orientation with equivalent amino acid side chains in panel A and with additional contact residues D87 (catalytic aspartate) and N140 (predicted OXA contact). Adapted from Rugel et al. (2020). Some secondary structure has been removed for clarity. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)