In the context of increasing demand for renewable alternatives of fuels and chemicals, the valorization of lignin emerges as a value-adding strategy in biorefineries and an alternative to petroleum-derived molecules. One of the compounds derived from lignin is ferulic acid (FA), which can be converted into valuable molecules such as vanillin. In microorganisms, FA biotransformation into vanillin can occur via a two-step reaction catalyzed by the sequential activity of a feruloyl-CoA synthetase (FCS) and an feruloyl-CoA hydratase-lyase (FCHL), which could be exploited industrially. In this study, a prokaryotic FCHL derived from a lignin-degrading microbial consortium (named LM-FCHL) was cloned, successfully expressed in soluble form and purified. The crystal structure was solved and refined at 2.1 Å resolution. The LM-FCHL is a hexamer composed of a dimer of trimers, which showed to be quite stable under extreme pH conditions. Finally, small angle X-ray scattering corroborates the hexameric state in solution and indicates flexibility in the protein structure. The present study contributes to the field of lignin valorization to valuable molecules by establishing the biophysical and structural characterization for a novel FCHL member of unique characteristics.

中文翻译：

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来自木质素降解财团的原核阿魏酰-CoA水合酶裂解酶的结构，在极端pH下具有高寡聚稳定性。

在对燃料和化学品的可再生替代品的需求不断增长的背景下，木质素的增值成为生物精炼厂的增值策略，并成为石油衍生分子的替代品。源自木质素的化合物之一是阿魏酸（FA），可以将其转化为有价值的分子，例如香兰素。在微生物中，FA转化为香兰素的过程可以通过两步反应发生，该步由阿魏酰辅酶A合成酶（FCS）和阿魏酰辅酶A水合酶裂解酶（FCHL）的顺序活性催化，可以在工业上利用。在这项研究中，从木质素降解微生物聚生体（命名为LM-FCHL）衍生的原核FCHL被克隆，以可溶形式成功表达并纯化。以2.1Å的分辨率解析并精炼了晶体结构。LM-FCHL是由三聚体的二聚体组成的六聚体，在极端pH条件下显示出非常稳定的特性。最后，小角度X射线散射证实了溶液中的六聚体状态，并表明了蛋白质结构的灵活性。本研究通过建立具有独特特征的新型FCHL成员的生物物理和结构表征，为有价值的分子的木质素增值领域做出了贡献。