Serial crystallography captures dynamic control of sequential electron and proton transfer events in a flavoenzyme

Manuel Maestre-Reyna (1) , Cheng-Han Yang (1) , Eriko Nango (2) , Wei-Cheng Huang (1) , Eka Putra Gusti Ngurah Putu (1) , Wen-Jin Wu (1) , Po-Hsun Wang (1) , Sophie Franz-Badur (3) , Martin Saft (3) , Hans-Joachim Emmerich (3) , Hsiang-Yi Wu (1) , Cheng-Chung Lee (4) , Kai-Fa Huang (1) , Yao-Kai Chang (1) , Jiahn-Haur Liao (1) , Jui-Hung Weng (1) , Wael Gad (1) , Chiung-Wen Chang (1) , Allan Pang (1) , Michihiro Sugahara (2) , Shigeki Owada (5) , Yuhei Hosokawa (6) , Yasumasa Joti (2) , Ayumi Yamashita (2) , Rie Tanaka (2) , Tomoyuki Tanaka (2) , Fangjia Luo (2) , Kensuke Tono (5) , Kai-Cheng Hsu (7) , Stephan Kiontke (3) , Igor Schapiro (8) , Roberta Spadaccini (9) , Antoine Royant (10, 11) , Junpei Yamamoto (6) , So Iwata (12) , Lars-Oliver Essen (3) , Yoshitaka Bessho (1, 12) , Ming-Daw Tsai (1, 13)

1 Academia Sinica
2 RIKEN - RIKEN - Institute of Physical and Chemical Research [Japon]
3 Philipps Universität Marburg = Philipps University of Marburg
4 Thin Film Technology Center
5 JASRI - Japan Synchrotron Radiation Research Institute [Hyogo]
6 Graduate School of Engineering Science [Toyonaka, Osaka]
7 Taipei Medical University
8 The Fritz Haber Research Center for Molecular Dynamics [Jerusalem]
9 Università degli Studi del Sannio
10 IBS - UMR 5075 - Institut de biologie structurale
11 ESRF - European Synchrotron Radiation Facility [Grenoble]
12 RIKEN RSC - RIKEN SPring-8 Center [Hyogo]
13 NTU - National Taiwan University [Taiwan]

Flavin coenzymes are universally found in biological redox reactions. DNA photolyases, with their flavin chromophore (FAD), utilize blue light for DNA repair and photoreduction. The latter process involves two single-electron transfers to FAD with an intermittent protonation step to prime the enzyme active for DNA repair. Here we use time-resolved serial femtosecond X-ray crystallography to describe how light-driven electron transfers trigger subsequent nanosecond-to-microsecond entanglement between FAD and its Asn/Arg-Asp redox sensor triad. We found that this key feature within the photolyase-cryptochrome family regulates FAD re-hybridization and protonation. After first electron transfer, the FAD•- isoalloxazine ring twists strongly when the arginine closes in to stabilize the negative charge. Subsequent breakage of the arginine-aspartate salt bridge allows proton transfer from arginine to FAD•-. Our molecular videos demonstrate how the protein environment of redox cofactors organizes multiple electron/proton transfer events in an ordered fashion, which could be applicable to other redox systems such as photosynthesis.

Domaines: Biologie structurale [q-bio.BM]

Manuel Maestre-Reyna, Cheng-Han Yang, Eriko Nango, Wei-Cheng Huang, Eka Putra Gusti Ngurah Putu, et al.. Serial crystallography captures dynamic control of sequential electron and proton transfer events in a flavoenzyme. Nature Chemistry, 2022, 14 (6), pp.677-685. ⟨10.1038/s41557-022-00922-3⟩. ⟨hal-03716098⟩