Figure 1. Phosphoethanolamine Transfer Reaction Catalysed by MCR-1.

Panel shows hexa-acylated E. coli lipid A structure⁵¹ with 1′ and 4′ phosphate groups. MCR-1 catalyses transfer of phosphoethanolamine from a phosphatidylethanolamine donor substrate onto lipid A. Figure shows addition of phosphoethanolamine to the 1′ position of lipid A, consistent with the proposed activity of Salmonella PmrC¹⁴.