@article {18753,
	title = {Spectroscopic and Structural Characterization of Reduced Desulfovibrio vulgaris Hildenborough W-FdhAB Reveals Stable Metal Coordination during Catalysis},
	journal = {ACS Chemical BiologyACS Chemical Biology},
	volume = {17},
	year = {2022},
	note = {<p>doi: 10.1021/acschembio.2c00336</p>
},
	month = {2022},
	pages = {1901 - 1909},
	publisher = {American Chemical Society},
	abstract = {<p>Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO2 reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Desulfovibrio vulgaris Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR. Titration with dithionite or formate leads to reduction of three [4Fe{\textendash}4S]1+ clusters, and full reduction requires Ti(III){\textendash}citrate. The redox potentials of the four [4Fe{\textendash}4S]1+ centers range between -250 and -530 mV. Two distinct WV signals were detected, WDV and WFV, which differ in only the g2-value. This difference can be explained by small variations in the twist angle of the two pyranopterins, as determined through DFT calculations of model compounds. The redox potential of WVI/V was determined to be -370 mV when reduced by dithionite and -340 mV when reduced by formate. The crystal structure of dithionite-reduced FdhAB was determined at high resolution (1.5 {\r A}), revealing the same structural alterations as reported for the formate-reduced structure. These results corroborate a stable six-ligand W coordination in the catalytic intermediate WV state of FdhAB.Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO2 reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Desulfovibrio vulgaris Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR. Titration with dithionite or formate leads to reduction of three [4Fe{\textendash}4S]1+ clusters, and full reduction requires Ti(III){\textendash}citrate. The redox potentials of the four [4Fe{\textendash}4S]1+ centers range between -250 and -530 mV. Two distinct WV signals were detected, WDV and WFV, which differ in only the g2-value. This difference can be explained by small variations in the twist angle of the two pyranopterins, as determined through DFT calculations of model compounds. The redox potential of WVI/V was determined to be -370 mV when reduced by dithionite and -340 mV when reduced by formate. The crystal structure of dithionite-reduced FdhAB was determined at high resolution (1.5 {\r A}), revealing the same structural alterations as reported for the formate-reduced structure. These results corroborate a stable six-ligand W coordination in the catalytic intermediate WV state of FdhAB.</p>
},
	isbn = {1554-8929},
	url = {https://doi.org/10.1021/acschembio.2c00336},
	author = {Ana Rita Oliveira and Mota, Cristiano and Klymanska, Kateryna and Biaso, Fr{\'e}d{\'e}ric and Rom{\~a}o, Maria Jo{\~a}o and Guigliarelli, Bruno and Pereira, In{\^e}s Cardoso}
}
