5yns
Crystal structure of PETase R280A mutant from Ideonella sakaiensis
Structural highlights
FunctionPETH_PISS1 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:29235460, PubMed:29374183, PubMed:29603535, PubMed:29666242, PubMed:32269349). 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:29374183, PubMed:29603535). Shows esterase activity towards p-nitrophenol-linked aliphatic esters (pNP-aliphatic esters) in vitro (PubMed:26965627, PubMed:30502092).[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedPlastics, including poly(ethylene terephthalate) (PET), possess many desirable characteristics and thus are widely used in daily life. However, non-biodegradability, once thought to be an advantage offered by plastics, is causing major environmental problem. Recently, a PET-degrading bacterium, Ideonella sakaiensis, was identified and suggested for possible use in degradation and/or recycling of PET. However, the molecular mechanism of PET degradation is not known. Here we report the crystal structure of I. sakaiensis PETase (IsPETase) at 1.5 A resolution. IsPETase has a Ser-His-Asp catalytic triad at its active site and contains an optimal substrate binding site to accommodate four monohydroxyethyl terephthalate (MHET) moieties of PET. Based on structural and site-directed mutagenesis experiments, the detailed process of PET degradation into MHET, terephthalic acid, and ethylene glycol is suggested. Moreover, other PETase candidates potentially having high PET-degrading activities are suggested based on phylogenetic tree analysis of 69 PETase-like proteins. Structural insight into molecular mechanism of poly(ethylene terephthalate) degradation.,Joo S, Cho IJ, Seo H, Son HF, Sagong HY, Shin TJ, Choi SY, Lee SY, Kim KJ Nat Commun. 2018 Jan 26;9(1):382. doi: 10.1038/s41467-018-02881-1. PMID:29374183[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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