Fig. 1
From: Structure of the catalytic domain of the colistin resistance enzyme MCR-1

Structure of lipid A of E. coli showing reaction catalyzed by MCR-1. Phosphatidylethanolamine’s R1 and R2 groups are constituted of acyl chains. The phosphoethanolamine moiety that is transferred from phosphatidylethanolamine to lipid A is shown in red. In this reaction, the transfer has been shown to occur to the 4’ position of lipid A, however, transfer can also occur to the 1’ position