Figure 8
From: Domain motions, dimerization, and membrane interactions of the murine guanylate binding protein 2
The binding of mGBP2 to mixed lipid membranes. (a) GFP-tagged mGBP2 accumulates at TexasRed-labeled GUVs containing cardiolipin (CL, left) but not at GUVs with phosphatidylserine (PS, right). (b) Simulations of mGBP2 bound to a DOPC/cholesterol/cardiolipin bilayer revealed large-scale motions of the M/E domain, as monitored by the distance (\(\Delta z\)) between residue L480 and the average position of the lipid head groups (red line). The results for the \(\hbox {mGBP2}_\text {CL-mem}^\text {GTP}\) system (cyan) are compared with the motions found for \(\hbox {mGBP2}_\text {mem}^\text {GTP}\) (brown) and \(\hbox {mGBP2}_\text {mem}^\text {noGTP}\) (orange). The snapshot on the right shows the conformation with the largest movement of the M/E domain (\(\Delta z=63.7\) Å), where the lipids are colored in ochre for DOPC, green for cholesterol, and cyan for cardiolipin. (c) The time-averaged residue–membrane interaction energies are decomposed into \(E_\mathrm{Coul}\) (blue) and \(E_\mathrm{LJ}\) (gray). The residues with a total interaction below \(-50\) kJ/mol (black line) are highlighted with red labels and considered as key residues for interaction with the membrane. They are both part of the E domain, as can be seen in the structure figure on the left.
