An In Silico Investigation of the Structural and Evolutionary Features of MAPEG Proteins in Bacteria

Abstract

The Membrane-Associated Proteins in Eicosanoid and Glutathione metabolism (MAPEG) superfamily comprises integral membrane proteins involved in lipid metabolism, detoxification, and redox regulation. While extensively characterised in eukaryotes, bacterial MAPEG homologs remain poorly understood. In this study, we conducted an in silico analysis of bacterial MAPEG proteins and performed a comparative investigation with selected eukaryotic homologs to assess structural conservation and evolutionary relationships. Sequence alignment and phylogenetic reconstruction showed that the bacterial proteins have the typical MAPEG signature motifs, including residues associated with glutathione binding. Homology modelling and structural prediction analyses indicated conservation of the characteristic trimeric transmembrane architecture typical of the MAPEG family. Comparative structural analysis highlighted a preserved core fold across domains of life, accompanied by variations in loop regions and membrane-embedded segments that may reflect adaptation to distinct cellular environments. Molecular docking simulations suggested a conserved glutathione-binding pocket, although subtle differences in the surrounding residues may influence substrate specificity. Overall, our findings support an evolutionarily conserved structural framework within the MAPEG superfamily and provide insight into the diversification of bacterial members relative to their eukaryotic homologs. This study contributes to a deeper understanding of MAPEG protein evolution and lays the groundwork for future functional and biochemical investigations.