7xtw
From Proteopedia
The structure of IsPETase in complex with MHET
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 PubMedPoly(butylene adipate-co-terephthalate) (PBAT), a polyester made of terephthalic acid (TPA), 1,4-butanediol, and adipic acid, is extensively utilized in plastic production and has accumulated globally as environmental waste. Biodegradation is an attractive strategy to manage PBAT, but an effective PBAT-degrading enzyme is required. Here, we demonstrate that cutinases are highly potent enzymes that can completely decompose PBAT films in 48 h. We further show that the engineered cutinases, by applying a double mutation strategy to render a more flexible substrate-binding pocket exhibit higher decomposition rates. Notably, these variants produce TPA as a major end-product, which is beneficial feature for the future recycling economy. The crystal structures of wild type and double mutation of a cutinase from Thermobifida fusca in complex with a substrate analogue are also solved, elucidating their substrate-binding modes. These structural and biochemical analyses enable us to propose the mechanism of cutinase-mediated PBAT degradation. Complete bio-degradation of poly(butylene adipate-co-terephthalate) via engineered cutinases.,Yang Y, Min J, Xue T, Jiang P, Liu X, Peng R, Huang JW, Qu Y, Li X, Ma N, Tsai FC, Dai L, Zhang Q, Liu Y, Chen CC, Guo RT Nat Commun. 2023 Mar 24;14(1):1645. doi: 10.1038/s41467-023-37374-3. PMID:36964144[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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