Multienzyme complexes, or metabolons, are natural assemblies or clusters of sequential enzymes in biosynthesis. Spatial proximity of the enzyme active sites results in a substrate channeling effect, streamlines the cascade reaction, and increases the overall efficiency of the metabolic pathway. Engineers have constructed synthetic multienzyme complexes to acquire better control of the metabolic flux and a higher titer of the target product. As most of these complexes are assembled through orthogonal interactions or bioconjugation reactions, the number of enzymes to be assembled is limited by the number of orthogonal interaction or reaction pairs. Here, we utilized the Tobacco mosaic virus (TMV) virus-like particle (VLP) as protein scaffold and orthogonal reactive protein pairs (SpyCatcher/SpyTag and SnoopCatcher/SnoopTag) as linker modules to assemble three terpene biosynthetic enzymes in Escherichia coli. The enzyme assembly switched on the production of amorpha-4,11-diene, whereas the product was undetectable in all the controls without assembly. This work demonstrates a facile strategy for constructing scaffolded catalytic nanomachineries to biosynthesize valuable metabolites in bacterial cells, and a unique assembly induced the switch-on mechanism in biosynthesis for the first time.

中文翻译：

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病毒样颗粒上组装的合成多酶复合物，用于纤维素的级联生物合成

多酶复合物或代谢产物是生物合成中顺序酶的天然装配或簇。酶活性位点的空间接近性导致底物通道效应，简化了级联反应，并提高了代谢途径的整体效率。工程师构建了合成的多酶复合物，以更好地控制代谢通量，并获得更高的目标产品滴度。由于大多数这些复合物是通过正交相互作用或生物缀合反应组装的，因此要组装的酶的数量受到正交相互作用或反应对的数量的限制。在这里，我们利用了烟草花叶病毒（TMV）病毒样颗粒（VLP）作为蛋白质支架，而正交反应蛋白对（SpyCatcher / SpyTag和SnoopCatcher / SnoopTag）作为接头模块在大肠杆菌中组装三种萜烯生物合成酶。酶的组装打开了amorpha-4,11-diene的生产，而在没有组装的所有对照中都无法检测到该产物。这项工作展示了一种构建支架式催化纳米机械以生物合成细菌细胞中有价值的代谢物的简便策略，并且独特的组装首次引发了生物合成中的开启机制。