8jmp
Structure of a leaf-branch compost cutinase, ICCG in complex with 1,4-butanediol terephthalate
Structural highlights
FunctionPETH_UNKP Catalyzes the hydrolysis of cutin, a polyester that forms the structure of plant cuticle (PubMed:22194294). Shows esterase activity towards p-nitrophenol-linked aliphatic esters (pNP-aliphatic esters), with a preference for short-chain substrates (C4 substrate at most) (PubMed:22194294, PubMed:24593046). Cannot hydrolyze olive oil (PubMed:22194294). Is also able to degrade poly(ethylene terephthalate), the most abundant polyester plastic in the world (PubMed:22194294, PubMed:32269349). Can also depolymerize poly(epsilon-caprolactone) (PCL), a synthetic aliphatic biodegradable polyester (PubMed:22194294).[1] [2] [3] Publication Abstract from PubMedPoly(butylene adipate-co-terephthalate) (PBAT) is among the most widely applied synthetic polyesters that are utilized in the packaging and agricultural industries, but the accumulation of PBAT wastes has posed a great burden to ecosystems. Using renewable enzymes to decompose PBAT is an eco-friendly solution to tackle this problem. Recently, we demonstrated that cutinase is the most effective PBAT-degrading enzyme and that an engineered cutinase termed TfCut-DM could completely decompose PBAT film to terephthalate (TPA). Here, we report crystal structures of a variant of leaf compost cutinase in complex with soluble fragments of PBAT, including BTa and TaBTa. In the TaBTa complex, one TPA moiety was located at a polymer-binding site distal to the catalytic center that has never been experimentally validated. Intriguingly, the composition of the distal TPA-binding site shows higher diversity relative to the one proximal to the catalytic center in various cutinases. We thus modified the distal TPA-binding site of TfCut-DM and obtained variants that exhibit higher activity. Notably, the time needed to completely degrade the PBAT film to TPA was shortened to within 24 h by TfCut-DM Q132Y (5813 mol per mol protein). Taken together, the structural information regarding the substrate-binding behavior of PBAT-degrading enzymes could be useful guidance for direct enzyme engineering. Remodeling the polymer-binding cavity to improve the efficacy of PBAT-degrading enzyme.,Yang Y, Cheng S, Zheng Y, Xue T, Huang JW, Zhang L, Yang Y, Guo RT, Chen CC J Hazard Mater. 2024 Feb 15;464:132965. doi: 10.1016/j.jhazmat.2023.132965. Epub , 2023 Nov 10. PMID:37979420[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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