Crystal structure of the plant feruloyl-coenzyme A monolignol transferase provides insights into the formation of monolignol ferulate conjugates.
Crystal structure of the plant feruloyl-coenzyme A monolignol transferase provides insights into the formation of monolignol ferulate conjugates.
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DOI：
10.1016/j.bbrc.2022.01.037
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发表时间：
2022-01
影响因子：
3.1
通讯作者：
Xi Liu;Shuliu Dai;Yu Zhou;Jinyue Liu;Dong Li;Jun Zhang;Yushan Zhu;Q. Zhao;Yue Feng;Yi Zhang
中科院分区：
文献类型：
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作者：
Xi Liu;Shuliu Dai;Yu Zhou;Jinyue Liu;Dong Li;Jun Zhang;Yushan Zhu;Q. Zhao;Yue Feng;Yi Zhang
木质素是一种高度复杂的酚类聚合物，对植物至关重要，但也使其难以工业加工。通过在木质素主链中引入相对不稳定的键来改造木质素可以使其更适合化学解聚。据报道，将当归的阿魏酰辅酶 A 木质素单体转移酶 (AsFMT) 引入杨树中，可以将阿魏酸单体缀合物 (ML-FA) 掺入木质素聚合物中，这表明了一种操纵植物易于解构的有前途的方法。 FMT 催化木质素单体和阿魏酰辅酶 A 之间的反应，产生 ML-FA 和游离辅酶 A-SH。然而，FMT 的底物特异性和催化过程的机制仍然知之甚少。在这里，我们报道了AsFMT的结构，它采用了BAHD酰基转移酶家族的典型折叠。与其他 BAHD 同系物的结构比较揭示了 AsFMT 的几个独特的结构特征，不同于 BAHD 同系物。进一步的分子对接研究表明，AsFMT 中的 T375 可能作为氧阴离子孔来稳定反应中间体，并提出 H278 在木质素单体的亲核羟基结合中的作用。总之，这项研究为 AsFMT 催化的反应提供了重要的结构见解，并将揭示其在木质素工程中的未来应用。
Lignin is a highly complex phenolic polymer which is essential for plants, but also makes it difficult for industrial processing. Engineering lignin by introducing relatively labile linkages into the lignin backbone can render it more amenable to chemical depolymerization. It has been reported that introducing a feruloyl-coenzyme A monolignol transferase fromAngelica sinensis(AsFMT) into poplar could incorporate monolignol ferulate conjugates (ML-FAs) into lignin polymers, suggesting a promising way to manipulate plants for readily deconstructing. FMT catalyzes a reaction between monolignols and feruloyl-CoA to produce ML-FAs and free CoA-SH. However, the mechanisms of substrate specificity and catalytic process of FMT remains poorly understood. Here we report the structure of AsFMT, which adopts a typical fold of BAHD acyltransferase family. Structural comparisons with other BAHD homologs reveal several unique structural features of AsFMT, different from those of the BAHD homologs. Further molecular docking studies showed that T375 in AsFMT may function as an oxyanion hole to stabilize the reaction intermediate and also proposed a role of H278 in the binding of the nucleophilic hydroxyl group of monolignols. Together, this study provides important structural insights into the reactions catalyzed by AsFMT and will shed light on its future application in lignin engineering.