Membrane models of E. coli containing cyclic moieties in the aliphatic lipid chain

► E. coli membranes consist of lipids with a cyclopropane moiety in the acyl-chain. ► New CHARMM lipid force field parameters are developed for these lipids. ► Hydrophobic thickness is underestimated without these cyclic-containing lipids. ► Hydrophobic matching of E. coli. transmembrane proteins is best with our model.