Fig. 4: Structural diversity of PET-active and representative enzymes from phylogenetic groups.

All structural models are shown to scale, rendered as cartoons with transparent accessible surface areas and putative active sites highlighted with the Ser-His-Asp catalytic triad in red sticks. A PET hydrolase scaffolds identified from mesophilic (top, I. sakaiensis PETase, PDB ID 6EQE³¹) and thermophilic (middle, LCC, PDB ID 4EB0²⁸, and bottom, T. fusca cutinase 1 DSM44342 (703; PDB ID 7QJR)) sources occupy a narrow structural space with highly conserved α/β hydrolase folds. B A selection of representatives from more distant phylogenetic groups reveals multiple additional and alternative structural features with substantial increases (102) and reductions (307) in the core fold. C Several additional distinct domains were revealed, including a Peripheral Subunit-Binding Domain (PSBD) and a Family 35 carbohydrate binding module (CBM).