8C16

Crystal structure of asymmetric ferredoxin/flavodoxin NADP+ oxidoreductase 2 (FNR2) H326V mutant from Bacillus cereus

Summary for 8C16

• Entry DOI: 10.2210/pdb8c16/pdb
• Related: 6GAS
• Descriptor: Ferredoxin--NADP reductase, FLAVIN-ADENINE DINUCLEOTIDE (2 entities in total)
• Functional Keywords: ferredoxin/flavodoxin reductase, electron transfer, fad, flavoprotein, oxidoreductase, mutant
• Biological source: Bacillus cereus ATCC 14579
• Total number of polymer chains: 4
• Total formula weight: 148587.48

Authors

Rugtveit, A.K.,Hammerstad, M.,Hersleth, H.-P. (deposition date: 2022-12-20, release date: 2023-07-12, Last modification date: 2024-02-07)

Primary citation

Hammerstad, M.,Rugtveit, A.K.,Dahlen, S.,Andersen, H.K.,Hersleth, H.P.
Functional Diversity of Homologous Oxidoreductases-Tuning of Substrate Specificity by a FAD-Stacking Residue for Iron Acquisition and Flavodoxin Reduction.
Antioxidants, 12:-, 2023

PubMed Abstract: Although bacterial thioredoxin reductase-like ferredoxin/flavodoxin NAD(P) oxidoreductases (FNRs) are similar in terms of primary sequences and structures, they participate in diverse biological processes by catalyzing a range of different redox reactions. Many of the reactions are critical for the growth, survival of, and infection by pathogens, and insight into the structural basis for substrate preference, specificity, and reaction kinetics is crucial for the detailed understanding of these redox pathways. () encodes three FNR paralogs, two of which have assigned distinct biological functions in bacillithiol disulfide reduction and flavodoxin (Fld) reduction. FNR2, the endogenous reductase of the Fld-like protein NrdI, belongs to a distinct phylogenetic cluster of homologous oxidoreductases containing a conserved His residue stacking the FAD cofactor. In this study, we have assigned a function to FNR1, in which the His residue is replaced by a conserved Val, in the reduction of the heme-degrading monooxygenase IsdG, ultimately facilitating the release of iron in an important iron acquisition pathway. The IsdG structure was solved, and IsdG-FNR1 interactions were proposed through protein-protein docking. Mutational studies and bioinformatics analyses confirmed the importance of the conserved FAD-stacking residues on the respective reaction rates, proposing a division of FNRs into four functionally unique sequence similarity clusters likely related to the nature of this residue.

PubMed: 37371954
DOI: 10.3390/antiox12061224

Experimental method

X-RAY DIFFRACTION (4.2 Å)