Novel Pet-Degrading Enzymes: Structure-Function from a Computational Perspective

The bacterium strain Ideonella sakaiensis 201-F6 is able to hydrolyze low-crystallinity PET films at 30 °C due to two enzymes named PETase and MHETase. Since its discovery, many efforts have been dedicated to elucidating the structure and features of those two enzymes, and various authors have highlighted the necessity to optimize both the substrate binding site and the global structure in order to enhance the stability and catalytic activity of these PET biocatalysts so as to make them more suitable for industrial applications. In this review, the strategies adopted by different research groups to investigate the structure and functionality of both PETase and MHETase in depth are described, emphasizing the advantages provided by the use of computational methods to complement and drive experiments. Subsequently, the modifications implemented with protein engineering are discussed. The versatility of the enzymes secreted by I. sakaiensis enables the prediction that they will find several applications in the disposal of PET debris, encouraging a prioritization of efforts in this prolific research field.