The structure of enzymes in complex with macromolecular substrates (proteins, DNAs, RNAs...) and the understanding of their mechanisms of recognition and action are still formidable challenges in biological chemistry today. We are particularly interested in transfer RNA modification enzymes, which play a vital role in the translation of genetic information. In particular, we are studying two classes of enzymes: iron-sulfur enzymes and flavoenzymes. For example, we have characterized an original mechanism of transfer RNA recognition by dihydrouridine synthase and proposed the existence of a [4Fe-5S] intermediate during transfer RNA sulfuration.
