Characterization and engineering of a two-enzyme system for plastics depolymerization

PETase depolymerizes PET, liberating soluble products, including mono(2-hydroxyethyl) terephthalate (MHET), which is cleaved to terephthalic acid and ethylene glycol by MHETase. Here, we report a 1.6 Å resolution MHETase structure, illustrating that the MHETase core domain is similar to PETase, capped by a lid domain. Simulations of the catalytic itinerary predict that MHETase follows the canonical two-step serine hydrolase mechanism. Bioinformatics analysis suggests that MHETase evolved from ferulic acid esterases, and two homologous enzymes are shown to exhibit MHET turnover. Analysis of the two homologous enzymes and the MHETase S131G mutant demonstrates the importance of this residue for accommodation of…

• NS
  National Science Foundation

  Awards: 1464946, 1552355, 1714556, 3900101301, DE-AC36-08GO28308, MCB-090159, CHE-1464946, MCB-1714556
• UD
  U.S. Department of Energy

  Awards: AC36-08GO28308, Contract DE-AC36-08GO28308, -AC36-08GO28308, DE-SC0011297TDD, 08GO28308
• UO
  University of Portsmouth

  Award: DE-AC36-08GO28308
• DL
  Diamond Light Source
• IN
  Iran National Science Foundation

  Awards: CBET-1552355, MCB-1714556
• NI
  National Institutes of Health

  Award: 1R01GM129519-01
• DF
  Directorate for Biological Sciences
• OO
  Office of Energy Efficiency and Renewable Energy

  Awards: AC36-08GO28308, DE-AC36-08GO28308
• BA
  Biotechnology and Biological Sciences Research Council

  Awards: BB/P011918/1, BB/P011918/1
• RE
  Research England

  Award: BB/P011918/1
• AM
  Advanced Manufacturing Office

  Awards: AC36-08GO28308, DE-AC36-08GO28308
• DO
  Division of Chemical, Bioengineering, Environmental, and Transport Systems

  Awards: 1552355, CBET-1552355
• DO
  Division of Chemistry

  Awards: 1464946, CHE-1464946
• OO
  Office of Energy Efficiency
• NR
  National Renewable Energy Laboratory

  Awards: Contract DE-AC36-08GO28308, AC36-08GO28308, DE-AC36-08GO28308