d‐Amino‐acid oxidases (DAAOs) catalyze the oxidative deamination of neutral and basic d‐amino acids. The DAAO from the thermophilic fungus Rasamsonia emersonii strain YA (ReDAAO) has a high thermal stability and a unique broad substrate specificity that includes the acidic d‐amino acid d‐Glu as well as various neutral and basic d‐amino acids. In this study, ReDAAO was crystallized by the hanging‐drop vapor‐diffusion method and its crystal structure was determined at a resolution of 2.00 Å. The crystal structure of the enzyme revealed that unlike other DAAOs, ReDAAO forms a homotetramer and contains an intramolecular disulfide bond (Cys230–Cys285), suggesting that this disulfide bond is involved in the higher thermal stability of ReDAAO. Moreover, the structure of the active site and its vicinity in ReDAAO indicates that Arg97, Lys99, Lys114 and Ser231 are candidates for recognizing the side chain of d‐Glu.

中文翻译：

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来自嗜热真菌 Rasamsonia emersonii YA 菌株的独特 d-氨基酸氧化酶的 X 射线结构分析

d-氨基酸氧化酶 (DAAO) 催化中性和碱性d-氨基酸的氧化脱氨。来自嗜热真菌Rasamsonia emersonii YA (ReDAAO)的 DAAO具有高热稳定性和独特的广泛底物特异性，包括酸性d-氨基酸d -Glu 以及各种中性和碱性d-氨基酸。在这项研究中，ReDAAO 通过悬滴气相扩散法结晶，其晶体结构以 2.00 Å 的分辨率确定。该酶的晶体结构显示，与其他 DAAO 不同，ReDAAO 形成同四聚体并包含分子内二硫键 (Cys230-Cys285)，表明该二硫键与 ReDAAO 的更高热稳定性有关。此外，ReDAAO 中活性位点及其附近的结构表明 Arg97、Lys99、Lys114 和 Ser231 是识别d -Glu侧链的候选者。