Third, the current work utilizes a somewhat larger membrane system, extends the duration of the production runs from 100 ns to 500 ns, and employs an 80:20 mix of lipids (POPE:POPG) that differs from the uniform composition (100 % dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE)) under which EptA was observed to undergo the striking conformational change described. Notably, such motions were not observed in simulations of EptA that used membranes comprising an 80:20 mixture of 1-palmitoyl-2-palmitoleyl-sn-glycero-3-phosphoethanolamine (PPoPE) and 20% 1,2-dimyristoyl-snglycero-3-phospho-(1'-rac)-glycerol (DMPG) i.e. closer to the conditions of those reported here. Anandan et al also provide experimental evidence for the existence of an "open" conformation of EptA based on SAXS curves acquired from recombinant protein incorporated into n-dodecylphosphocholine (DPC) micelles , while cautioning that DPC is a known destabilizer of some membrane protein systems. Of note, the "open" conformation was not observed in equivalent experiments using DDM micelles. Overall, while it appears clear that the two domains of bacterial phosphoethanolamine transferases such as EptA or MCR-1 are able to move relative to one another, comparison of available data indicates that in both laboratory investigations and simulations the extent of such movements is strongly dependent upon the local environment.