Abstract：
Ergothioneine is a sulfur-containing metabolite that is produced by bacteria and fungi, and is absorbed by plants and animals as a micronutrient. Ergothioneine reacts with harmful oxidants, including singlet oxygen and hydrogen peroxide, and may therefore protect cells against oxidative stress. Herein we describe two enzymes from actinobacteria that cooperate in the specific oxidative degradation of ergothioneine. The first enzyme is an iron-dependent thiol dioxygenase that produces ergothioneine sulfinic acid. A crystal structure of ergothioneine dioxygenase from Thermocatellispora tengchongensis reveals many similarities with cysteine dioxygenases, suggesting that the two enzymes share a common mechanism. The second enzyme is a metal-dependent ergothioneine sulfinic acid desulfinase that produces Nα-trimethylhistidine and SO2 . The discovery that certain actinobacteria contain the enzymatic machinery for O2 -dependent biosynthesis and O2 -dependent degradation of ergothioneine indicates that these organisms may actively manage their ergothioneine content.
摘要：
麦角硫因是由细菌和真菌产生的含硫代谢产物,被植物和动物吸收作为微量营养素。麦角硫因与有害的氧化剂反应，包括单线态氧和过氧化氢,因此可以保护细胞免受氧化应激。在本文中，我们描述了两种来自放线菌的酶，它们在麦角硫因的特定氧化降解中协同作用。第一种酶是产生麦角硫酮亚磺酸的铁依赖性硫醇双加氧酶。来自Thermocatellisporatenggchongensis的麦角硫因双加氧酶的晶体结构揭示了与半胱氨酸双加氧酶的许多相似之处，这表明这两种酶具有共同的机制。第二种酶是金属依赖性麦角硫素亚磺酸脱硫酶，可产生Nα-三甲基组氨酸和SO2。某些放线菌含有依赖O2的生物合成和依赖O2的麦角硫因降解的酶机制，这表明这些生物可以积极地控制其麦角硫因含量。
