Structural Insights into a Fusion Protein between a Glutaredoxin-like and a Ferredoxin-Disulfide Reductase Domain from an Extremophile Bacterium
Abstract
In eukaryotic photosynthetic organisms, ferredoxin–thioredoxin reductases (FTRs) are key proteins reducing several types of chloroplastic thioredoxins (TRXs) in light conditions. The electron cascade necessary to reduce oxidized TRXs involves a pair of catalytic cysteines and a [4Fe–4S] cluster present at the level of the FTR catalytic subunit, the iron–sulfur cluster receiving electrons from ferredoxins. Genomic analyses revealed the existence of FTR orthologs in non-photosynthetic organisms, including bacteria and archaea, referred to as ferredoxin-disulfide reductase (FDR) as they reduce various types of redoxins. In this study, we describe the tridimensional structure of a natural hybrid protein formed by an N-terminal glutaredoxin-like domain fused to a FDR domain present in the marine bacterium Desulfotalea psychrophila Lsv54. This structure provides information on how and why the absence of the variable subunit present in FTR heterodimer which normally protects the Fe–S cluster is dispensable in FDR proteins. In addition, modelling of a tripartite complex based on the existing structure of a rubredoxin (RBX)–FDR fusion present in anaerobic methanogen archaea allows recapitulating the electron flow involving these RBX, FDR and GRX protein domains.
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BibTeX
@article{zannini2026structural,
title = {{Structural Insights into a Fusion Protein between a Glutaredoxin-like and a Ferredoxin-Disulfide Reductase Domain from an Extremophile Bacterium}},
author = {Flavien Zannini and Sandrine Mathiot and Jérémy Couturier and Claude Didierjean and Nicolas Rouhier},
journal = {Inorganics},
year = {2026},
month = sep,
doi = {10.3390/inorganics10020024},
url = {https://hal.science/hal-03610879v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Structural Insights into a Fusion Protein between a Glutaredoxin-like and a Ferredoxin-Disulfide Reductase Domain from an Extremophile Bacterium
AU - Flavien Zannini
AU - Sandrine Mathiot
AU - Jérémy Couturier
AU - Claude Didierjean
AU - Nicolas Rouhier
PY - 2026
DA - 2026/09/02
JO - Inorganics
DO - 10.3390/inorganics10020024
UR - https://hal.science/hal-03610879v1
AB - In eukaryotic photosynthetic organisms, ferredoxin–thioredoxin reductases (FTRs) are key proteins reducing several types of chloroplastic thioredoxins (TRXs) in light conditions. The electron cascade necessary to reduce oxidized TRXs involves a pair of catalytic cysteines and a [4Fe–4S] cluster present at the level of the FTR catalytic subunit, the iron–sulfur cluster receiving electrons from ferredoxins. Genomic analyses revealed the existence of FTR orthologs in non-photosynthetic organisms, including bacteria and archaea, referred to as ferredoxin-disulfide reductase (FDR) as they reduce various types of redoxins. In this study, we describe the tridimensional structure of a natural hybrid protein formed by an N-terminal glutaredoxin-like domain fused to a FDR domain present in the marine bacterium Desulfotalea psychrophila Lsv54. This structure provides information on how and why the absence of the variable subunit present in FTR heterodimer which normally protects the Fe–S cluster is dispensable in FDR proteins. In addition, modelling of a tripartite complex based on the existing structure of a rubredoxin (RBX)–FDR fusion present in anaerobic methanogen archaea allows recapitulating the electron flow involving these RBX, FDR and GRX protein domains.
SN - 2304-6740
ER -