Structural insight into molecular mechanism of poly(ethylene terephthalate) degradation.
Structural insight into molecular mechanism of poly(ethylene terephthalate) degradation.
复制标题
对聚乙二醇乙酸乙酯）降解的分子机制的结构洞察力。
DOI：
10.1038/s41467-018-02881-1
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发表时间：
2018-01-26
影响因子：
16.6
通讯作者：
Kim KJ
中科院分区：
文献类型：
--
作者：
Joo S;Cho IJ;Seo H;Son HF;Sagong HY;Shin TJ;Choi SY;Lee SY;Kim KJ
包括聚对苯二甲酸乙二醇酯（PET）在内的塑料具有许多理想的特性，因此广泛用于日常生活中。然而，非生物降解性，一度被认为是塑料提供的优势，正在造成重大的环境问题。最近，PET降解细菌，Ideonella sakaiensis，被鉴定并建议用于PET的降解和/或回收。然而，PET降解的分子机制尚不清楚。在这里，我们报告的晶体结构I。sakaiensis PETase（IsPETase），分辨率为1.5 μ m。IsPETase在其活性位点具有Ser-His-Asp催化三联体，并含有最佳底物结合位点以容纳PET的四个单羟乙基对苯二甲酸酯（MHET）部分。基于结构和定点突变实验，PET降解成MHET，对苯二甲酸，和乙二醇的详细过程的建议。此外，其他PETase候选人可能具有高的PET降解活动的建议基于系统发育树分析的69 PETase样蛋白。聚对苯二甲酸乙二酯（PET）是一种广泛使用的塑料，其在环境中的累积已成为全球性问题。在这里，作者报告了Ideonella sakaiensis PET降解酶的晶体结构，并提出了PET降解的分子机制。
Plastics, 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 Å 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. Poly(ethylene terephthalate) (PET) is a widely used plastic and its accumulation in the environment has become global problem. Here the authors report the crystal structure of a Ideonella sakaiensis PET-degrading enzyme and propose a molecular mechanism for PET degradation.