Diacylglycerol Kinase A Is Essential for Polymyxin Resistance Provided by EptA, MCR-1, and Other Lipid A Phosphoethanolamine Transferases

For Gram-negative bacteria, modification of a key surface structure known as lipopolysaccharide (LPS) is critical for resistance to cationic antimicrobial peptides, including the last-resort antibiotic polymyxin. One key enzyme that is critical for resistance is EptA that adds a positively charged residue to LPS, preventing polymyxin binding. Here we show that EptA can be posttranscriptionally regulated by a key cell envelope lipid leading to changes in antibiotic resistance.