Revisiting the co-crystal structure of a DNA glycosylase with photocaged substrate: a suitable time-resolved crystallography target?
Journal
IUCrJ
Journal Volume
12
Journal Issue
5
Start Page
515
End Page
522
ISSN
2052-2525
Date Issued
2025-07-14
Author(s)
Imura, Tomoki
Hosokawa, Yuhei
Yang, Kai-Chun
Ban, Yuki
Shih, Hsuan-Yu
Yamamoto, Junpei
Abstract
Co-crystal structures of a base-excision DNA-repair enzyme (human 8-oxo-guanine DNA glycosylase; hOgg1) in complex with a photocaged 8-oxoguanine DNA lesion were determined before and after uncaging via illumination at 2.81 and 2.48 Å resolution, respectively. The structures were carefully reassessed to rapidly expand the target repertoire of light-triggered time-resolved macromolecular crystallography. Late-intermediate cryo-trapping after uncaging revealed the partial accommodation of 8-oxoguanine in the active site with 68% occupancy, which did not induce full active-site adaptation to the catalytic state. Crystal illumination led to a light-dependent loss of diffraction power, likely due to crystal-packing collapse during the very late reaction stages. This work therefore not only demonstrates that hOgg1 is well suited for time-resolved crystallography, but also that such analysis is necessary to determine further steps in its reaction.
Subjects
DNA repair
hOgg1
intermediate trapping
photocaged substrate analogs
SDGs
Publisher
International Union of Crystallography (IUCr)
Type
journal article