Background: UDP-glucuronosyltransferases (UGTs) play a crucial role in maintaining endobiotic homeostasis and metabolizing xenobiotic compounds, particularly clinical drugs. However, the detailed catalytic mechanism of UGTs has not been fully elucidated due to the limited availability of reliable protein structures. Determining the catalytic domain of human UGTs has proven to be a significant challenge, primarily due to the difficulty in purifying and crystallizing the full-length protein. Objective: This study focused on the human UGT2B10 C-terminal cofactor binding domain, aiming to provide structural insights into the fundamental catalytic mechanisms. Method: In this study, the C-terminal sugar-donor binding domain of human UGT2B10 was purified and crystallized using the vapor-diffusion method. The resulting UGT2B10 CTD crystals displayed high-quality diffraction patterns, allowing for data collection at an impressive resolution of 1.53 Å using synchrotron radiation. Subsequently, the structure of the UGT2B10 CTD was determined using the molecule replacement method with a homologous structure. Results: The crystals were monoclinic, belonging to the space C2 with unit-cell parameters a = 85.90 Å, b = 58.39 Å, c = 68.87 Å, α = γ = 90°, and β = 98.138°. The Matthews coefficient VM was determined to be 2.24 Å3 Da-1 (solvent content 46.43%) with two molecules in the asymmetric unit. Conclusion: The crystal structure of UGT2B10 CTD was solved at a high resolution of 1.53 Å, revealing a conserved cofactor binding pocket. This is the first study determining the C-terminal cofactor binding domain of human UGT2B10, which plays a key role in additive drug metabolism

中文翻译：

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人 UDP-葡萄糖醛酸基转移酶 2B10 核苷酸-糖结合域的晶体结构测定

背景：UDP-葡萄糖醛酸基转移酶（UGT）在维持内生稳态和代谢外源化合物（特别是临床药物）方面发挥着至关重要的作用。然而，由于可靠的蛋白质结构有限，UGT 的详细催化机制尚未完全阐明。确定人类 UGT 的催化结构域已被证明是一项重大挑战，主要是由于纯化和结晶全长蛋白质的困难。目的：本研究重点关注人 UGT2B10 C 末端辅因子结合域，旨在为基本催化机制提供结构见解。方法：本研究采用蒸气扩散法纯化并结晶人 UGT2B10 的 C 端糖供体结合结构域。由此产生的 UGT2B10 CTD 晶体显示出高质量的衍射图案，允许使用同步加速器辐射以令人印象深刻的 1.53 Å 分辨率收集数据。随后，利用同源结构的分子置换法确定了UGT2B10 CTD的结构。结果：晶体为单斜晶系，属于C2空间，晶胞参数为a = 85.90 Å，b = 58.39 Å，c = 68.87 Å，α = γ = 90°，β = 98.138°。不对称单元中有两个分子时，马修斯系数 VM 确定为 2.24 Å3 Da-1（溶剂含量 46.43%）。结论：以 1.53 Å 的高分辨率解析了 UGT2B10 CTD 的晶体结构，揭示了保守的辅因子结合袋。这是第一项确定人 UGT2B10 C 端辅因子结合域的研究，该域在附加药物代谢中发挥关键作用