台湾大学Ming-Daw Tsai团队通过光解酶在原子分辨率下观察DNA修复过程。相关研究成果于2023年12月1日发表在《科学》。

光解酶是一类普遍存在的黄素蛋白，它利用蓝光来修复DNA的光解。

该文中，研究人员使用时间分辨串行飞秒晶体学（TR-SFX）确定了光裂酶催化修复环丁烷嘧啶二聚体（CPD）损伤的结构机制。研究人员获得了18张快照，显示了四个反应位点的时间依赖性变化。利用这些结果制作了一部电影，描述了在皮秒到纳秒范围内修复CPD损伤，然后恢复参与催化的酶部分，在500纳秒内完成完全还原的酶产物复合物的形成。

最后，在25到200微秒捕获胸腺嘧啶碱基的反向翻转中间体以重新连接DNA。该数据涵盖了光解酶的完整分子机制，重要的是，涵盖了其在宽时间尺度和原子分辨率下的化学和酶催化作用。

附：英文原文

Title: Visualizing the DNA repair process by a photolyase at atomic resolution

Author: Manuel Maestre-Reyna, Po-Hsun Wang, Eriko Nango, Yuhei Hosokawa, Martin Saft, Antonia Furrer, Cheng-Han Yang, Eka Putra Gusti Ngurah Putu, Wen-Jin Wu, Hans-Joachim Emmerich, Nicolas Caramello, Sophie Franz-Badur, Chao Yang, Sylvain Engilberge, Maximilian Wranik, Hannah Louise Glover, Tobias Weinert, Hsiang-Yi Wu, Cheng-Chung Lee, Wei-Cheng Huang, Kai-Fa Huang, Yao-Kai Chang, Jiahn-Haur Liao, Jui-Hung Weng, Wael Gad, Chiung-Wen Chang, Allan H. Pang, Kai-Chun Yang, Wei-Ting Lin, Yu-Chen Chang, Dardan Gashi, Emma Beale, Dmitry Ozerov, Karol Nass, Gregor Knopp, Philip J. M. Johnson, Claudio Cirelli, Chris Milne, Camila Bacellar, Michihiro Sugahara, Shigeki Owada, Yasumasa Joti, Ayumi Yamashita, Rie Tanaka, Tomoyuki Tanaka, Fangjia Luo, Kensuke Tono, Wiktoria Zarzycka, Pavel Müller, Maisa Alkheder Alahmad, Filipp Bezold, Valerie Fuchs, Petra Gnau, Stephan Kiontke, Lukas Korf, Viktoria Reithofer, Christian Joshua Rosner, Elisa Marie Seiler, Mohamed Watad, Laura Werel, Roberta Spadaccini, Junpei Yamamoto, So Iwata, Dongping Zhong, Jrg Standfuss, Antoine Royant, Yoshitaka Bessho, Lars-Oliver Essen, Ming-Daw Tsai

Issue&Volume: 2023-12-01

Abstract: Photolyases, a ubiquitous class of flavoproteins, use blue light to repair DNA photolesions. In this work, we determined the structural mechanism of the photolyase-catalyzed repair of a cyclobutane pyrimidine dimer (CPD) lesion using time-resolved serial femtosecond crystallography (TR-SFX). We obtained 18 snapshots that show time-dependent changes in four reaction loci. We used these results to create a movie that depicts the repair of CPD lesions in the picosecond-to-nanosecond range, followed by the recovery of the enzymatic moieties involved in catalysis, completing the formation of the fully reduced enzyme-product complex at 500 nanoseconds. Finally, back-flip intermediates of the thymine bases to reanneal the DNA were captured at 25 to 200 microseconds. Our data cover the complete molecular mechanism of a photolyase and, importantly, its chemistry and enzymatic catalysis at work across a wide timescale and at atomic resolution.

DOI: add7795

Source: https://www.science.org/doi/10.1126/science.add7795