Structural evidence for a reaction intermediate mimic in the active site of a sulfite dehydrogenase

Ahmed Djeghader (1) , Melanie Rossotti (2) , Saleh Abdulkarim (3) , Frédéric Biaso (2) , Guillaume Gerbaud (2) , Wolfgang Nitschke (2) , Barbara Schoepp-Cothenet (2) , Tewfik Soulimane (3) , Stéphane Grimaldi (2)

1 URMITE - Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes
2 BIP - Bioénergétique et Ingénierie des Protéines
3 UL - University of Limerick

By combining X-ray crystallography, electron paramagnetic resonance techniques and density functional theory-based modelling, we provide evidence for a direct coordination of the product analogue, phosphate, to the molybdenum active site of a sulfite dehydrogenase. This interaction is mimicking the still experimentally uncharacterized reaction intermediate proposed to arise during the catalytic cycle of this class of enzymes. This work opens new perspectives for further deciphering the reaction mechanism of this nearly ubiquitous class of oxidoreductases.

Domaines: Biologie structurale [q-bio.BM]

Ahmed Djeghader, Melanie Rossotti, Saleh Abdulkarim, Frédéric Biaso, Guillaume Gerbaud, et al.. Structural evidence for a reaction intermediate mimic in the active site of a sulfite dehydrogenase. Chemical Communications, 2020, 56 (68), pp.9850-9853. ⟨10.1039/D0CC03634J⟩. ⟨hal-02930401⟩