7F76

Crystal Structure of FMN-dependent NADPH-quinone reductase (azoR) from Bacillus cohnii

Summary for 7F76

• Entry DOI: 10.2210/pdb7f76/pdb
• Descriptor: FMN-dependent NADPH-quinone reductase (azoR), FLAVIN MONONUCLEOTIDE, ISOPROPYL ALCOHOL, ... (5 entities in total)
• Functional Keywords: quinone reductase (azor), fmn, nadh, oxidoreductase
• Biological source: Bacillus cohnii
• Total number of polymer chains: 2
• Total formula weight: 45009.10

Authors

Yoneda, K.,Sakuraba, H.,Ohshima, T. (deposition date: 2021-06-28, release date: 2022-05-11, Last modification date: 2025-05-14)

Primary citation

Yoneda, K.,Sakuraba, H.,Hayashi, J.,Naruse, Y.,Araki, T.,Ohshima, T.
Structural and Functional Characteristics of FMN-Dependent NADPH-Indigo Reductase Homolog from Bacillus cohnii.
J Nutr Sci Vitaminol (Tokyo), 71:180-183, 2025

PubMed Abstract: We found indigo reductase homolog in Bacillus cohnii gene and succeeded in production of a large amount of the recombinant homolog in Escherichia coli. The homolog exhibited FMN-dependent NADPH-quinone reductase activity, but not indigo-reducing activity. Crystal structure analysis of the enzyme revealed the formation of a binary complex with FMN, 2-propanol, and glycerol, determined at a resolution of 1.57 Å. Notably, the structure of FMN was of particular interest, as the isoalloxazine ring of FMN exhibited a butterfly-like bent conformation, with an angular deviation of approximately 9.4º to 10.9º along the axis between N5 and N10. The reason for FMN adopting a butterfly-like structure was thought that the exposure of the enzyme crystal to X-ray radiation led to the one-electron reduction of FMN, forming the semiquinone radical FMNH.

PubMed: 40301060
DOI: 10.3177/jnsv.71.180

Experimental method

X-RAY DIFFRACTION (1.57 Å)