Biochemical and structural characterization of an aromatic ring-hydroxylating dioxygenase for terephthalic acid catabolism.
Biochemical and structural characterization of an aromatic ring-hydroxylating dioxygenase for terephthalic acid catabolism.
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对苯二甲酸催化剂芳环羟基化双加氧酶的生化和结构表征。
DOI：
10.1073/pnas.2121426119
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发表时间：
2022-03-29
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
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作者：
每年产生超过4亿吨塑料垃圾，其中绝大多数最终被填埋。针对塑料的生物转化战略已成为实现合成塑料循环经济的重要组成部分，特别是那些表现出与自然界中发现的化学键相似的化学键的合成塑料，如聚酯。在这项工作中描述的酶系统是必不可少的矿化的异生组分的聚对苯二甲酸乙二醇酯（PET）在生物圈中。我们对其结构和底物偏好的描述为PET升级循环系统的体内或体外工程奠定了基础。几种细菌具有合成聚酯聚（对苯二甲酸乙二醇酯）（PET）的分解代谢途径的组分。这些通过将聚合物的酯键水解成其单体乙二醇和对苯二甲酸酯（TPA）来进行，其进一步转化为常见的代谢物。这些途径对于PET升级循环的基因工程微生物至关重要，从而引发了对其基本生物化学和结构阐明的兴趣。对苯二甲酸双加氧酶（TPADO）及其同源还原酶组成了一个复杂的多金属酶系统，它使TPA二羟基化，激活它进行酶促脱羧以产生原儿茶酸（PCA）。在这里，我们报告TPADO的结构，生化和生物信息学分析。总之，这些数据说明了显着的适应TPADO的TPA二价阴离子作为其优选的基板，与小，质子化的环2-碳取代基之间的少数允许的基板修改。TPADO是一种Rieske [2Fe 2S]和单核非血红素铁依赖性加氧酶（Rieske加氧酶），与其家族的大多数结构特征成员具有低序列相似性。结构数据显示，α-螺旋相关的组氨酸侧链在底物结合到相邻口袋中后旋转到Fe（II）配位位置。TPA与侧链在这个口袋中的相互作用是不保守的同源物具有不同的底物偏好。不太对称的2-羟基-TPA底物的结合模式，PCA是其氧化产物的观察，以及TPADO α-亚基与邻氨基苯甲酸双加氧酶的密切关系，使我们能够提出一个基于结构的产物形成模型。未来的努力，以确定，发展，或工程TPADO的变种所需的性能将使这里所描述的结果。
More than 400 million tons of plastic waste is produced each year, the overwhelming majority of which ends up in landfills. Bioconversion strategies aimed at plastics have emerged as important components of enabling a circular economy for synthetic plastics, especially those that exhibit chemically similar linkages to those found in nature, such as polyesters. The enzyme system described in this work is essential for mineralization of the xenobiotic components of poly(ethylene terephthalate) (PET) in the biosphere. Our description of its structure and substrate preferences lays the groundwork for in vivo or ex vivo engineering of this system for PET upcycling. Several bacteria possess components of catabolic pathways for the synthetic polyester poly(ethylene terephthalate) (PET). These proceed by hydrolyzing the ester linkages of the polymer to its monomers, ethylene glycol and terephthalate (TPA), which are further converted into common metabolites. These pathways are crucial for genetically engineering microbes for PET upcycling, prompting interest in their fundamental biochemical and structural elucidation. Terephthalate dioxygenase (TPADO) and its cognate reductase make up a complex multimetalloenzyme system that dihydroxylates TPA, activating it for enzymatic decarboxylation to yield protocatechuic acid (PCA). Here, we report structural, biochemical, and bioinformatic analyses of TPADO. Together, these data illustrate the remarkable adaptation of TPADO to the TPA dianion as its preferred substrate, with small, protonatable ring 2-carbon substituents being among the few permitted substrate modifications. TPADO is a Rieske [2Fe2S] and mononuclear nonheme iron-dependent oxygenase (Rieske oxygenase) that shares low sequence similarity with most structurally characterized members of its family. Structural data show an α-helix–associated histidine side chain that rotates into an Fe (II)–coordinating position following binding of the substrate into an adjacent pocket. TPA interactions with side chains in this pocket were not conserved in homologs with different substrate preferences. The binding mode of the less symmetric 2-hydroxy-TPA substrate, the observation that PCA is its oxygenation product, and the close relationship of the TPADO α-subunit to that of anthranilate dioxygenase allowed us to propose a structure-based model for product formation. Future efforts to identify, evolve, or engineer TPADO variants with desirable properties will be enabled by the results described here.
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DOI：
10.1016/j.bbapap.2015.04.015
发表时间：
2015-08
影响因子：
3.2
作者：
Gerlt, John A.;Bouvier, Jason T.;Davidson, Daniel B.;Imker, Heidi J.;Sadkhin, Boris;Slater, David R.;Whalen, Katie L.
通讯作者：
Whalen, Katie L.
影响因子：
--
作者：
Kweon O;Kim SJ;Baek S;Chae JC;Adjei MD;Baek DH;Kim YC;Cerniglia CE
通讯作者：
Cerniglia CE
影响因子：
4.4
作者：
Fukuhara, Yuki;Inakazu, Keisuke;Masai, Eiji
通讯作者：
Masai, Eiji
影响因子：
3.2
作者：
Ferraro, Daniel J.;Okerlund, Adam L.;Ramaswamy, S.
通讯作者：
Ramaswamy, S.
影响因子：
12.9
作者：
Kim, Dong Hyun;Han, Dong Oh;Kim, Kyoung Heon
通讯作者：
Kim, Kyoung Heon