Résumé
Fungal Oligopeptide Transporters (Fot) have been described as a family of di- and tripeptide transportersin fungi. In Saccharomyces cerevisiae, Fot are only present in wine strains as a result of a horizontal genetransfer (HGT) from the yeast Torulaspora microellipsoides. The S. cerevisiae wine strain 59A, haploidderivative of the EC1118 strain which contains Fot1 and Fot2, displays a better fermentation performanceand higher cell viability by the end of fermentation than its Fot-knockout counterpart; additionally, thehigher capacity to consume oligopeptides due to Fot is also responsible for a more positive aroma profileof the strain 59A during wine fermentation, with a lower production of acetate and higher production ofester acetates and fusel alcohols. These results evidenced the adaptive advantage conferred by Fot to S.cerevisiae within the wine environment, also highlighting the interest in using Fot-containing strains forwinemaking. Despite the benefits associated with Fot, little is still known about this family oftransporters. Recently, we have reported that Fot members in S. cerevisiae and T. microellipsoides havedifferent oligopeptide specificities despite their high sequence identity. To explain these differences, wehave combined AlphaFold modelling and molecular docking with selected oligopeptides as ligands topropose a mechanism for substrate binding. Our findings point at highly conserved residues located at theloose segments in transmembrane domains 1 and 6 as to shape the binding site of Fot, suggesting thatvariable sites among Fot members, localized in the N-terminal domains and inter-transmembrane regions,may be responsible for their distinct oligopeptide uptake abilities. We have studied the conservation ofthe candidate residues for substrate binding in a dataset of putative Fot sequences identified through acurated strategy. With a limited number of sequences found in Basidiomycota yeast species, homologousFOT gene sequences were mainly identified in Ascomycete yeasts and filamentous fungal species fromthe Eurotiales order. Phylogenetic reconstruction of putative Fot members in Ascomycota reveals apatchy distribution that indicates more potential cases of HGT or gene duplications