Involved in the degradation and assimilation of the plastic poly(ethylene terephthalate) (PET), which allows I.sakaiensis to use PET as its major energy and carbon source for growth. Likely acts synergistically with MHETase to depolymerize PET (PubMed:26965627). Catalyzes the hydrolysis of PET to produce mono(2-hydroxyethyl) terephthalate (MHET) as the major product (PubMed:26965627, PubMed:32269349, PubMed:29666242, PubMed:29603535, PubMed:29374183, PubMed:29235460). Also depolymerizes another semiaromatic polyester, poly(ethylene-2,5-furandicarboxylate) (PEF), which is an emerging, bioderived PET replacement with improved gas barrier properties (PubMed:29666242). In contrast, PETase does not degrade aliphatic polyesters such as polylactic acid (PLA) and polybutylene succinate (PBS) (PubMed:29666242). Is also able to hydrolyze bis(hydroxyethyl) terephthalate (BHET) to yield MHET with no further decomposition, but terephthalate (TPA) can also be observed (PubMed:26965627, PubMed:29603535, PubMed:29374183). Shows esterase activity towards p-nitrophenol-linked aliphatic esters (pNP-aliphatic esters) in vitro (PubMed:26965627, PubMed:30502092). (ethylene terephthalate)(n) + H2O = (ethylene terephthalate)(n-1) + 4-[(2-hydroxyethoxy)carbonyl]benzoate + H(+) (2,5-ethylene furandicarboxylate)(n) + 2 H2O = (2,5-ethylene furandicarboxylate)(n-1) + 2,5-dicarboxyfuran + ethylene glycol + 2 H(+) an acetyl ester + H2O = acetate + an aliphatic alcohol + H(+) a butanoate ester + H2O = an aliphatic alcohol + butanoate + H(+) a hexanoate ester + H2O = an aliphatic alcohol + H(+) + hexanoate an octanoate ester + H2O = an aliphatic alcohol + H(+) + octanoate a dodecanoate ester + H2O = an aliphatic alcohol + dodecanoate + H(+) Salts and glycerol enhance the enzymatic activity in vitro towards pNP-esters, while detergents and organic solvents reduce the enzymatic activity. kcat is 1590 sec(-1) for the hydrolysis of pNP-acetate. kcat is 1353 sec(-1) for the hydrolysis of pNP-butanoate. kcat is 1345 sec(-1) for the hydrolysis of pNP-hexanoate. kcat is 519 sec(-1) for the hydrolysis of pNP-octanoate. kcat is 1531 sec(-1) for the hydrolysis of pNP-dodecanoate. Optimum pH is 9 for PET film hydrolysis (PubMed:26965627). Optimum pH is 9 for PET (commercial drinking bottle) hydrolysis. Optimum pH is 6.5-8.0 for BHET hydrolysis (PubMed:29603535). Optimum pH is 8.0 for the hydrolysis of pNP-esters. The enzyme is active at pH 6-10, has an optimal pH range of 7-9 and it is rapidly inactivated below pH 7.0 or above pH 9.0 (PubMed:30502092). Optimum temperature is 40 degrees Celsius for PET film hydrolysis (PubMed:26965627). Optimum temperature is 30 degrees Celsius for PET (commercial drinking bottle) hydrolysis and BHET hydrolysis (PubMed:29603535). Optimum temperature is 35-45 degrees Celsius for the hydrolysis of pNP-esters. Remains active even at 65 degrees Celsius (about 60% of maximum activity) (PubMed:30502092). Xenobiotic degradation. Monomer. Highly up-regulated during growth on PET film. PETase retains the ancestral alpha/beta-hydrolase fold but exhibits a more open active-site cleft than homologous cutinases. Has potential for application in environmental remediation and biological recycling of PET and PEF waste products. Belongs to the AB hydrolase superfamily. Of plastic and men - Issue 181 of July 2016