CXCR1-PIP lipid interactions. (A) Shown is a protein surface presentation of the number of contacts with PIP lipids (increasing number of contacts corresponds to Blue-White-Red color change) viewed in the plane parallel to the bilayer (showing helices one to four and five to eight on the left and right figure, respectively) and normal to the bilayer (showing example snapshots of PIP lipids—in magenta—bound to the protein). (B) Center-of-mass distances between key residues in each interaction site are identified with PIP lipids. For this particular case, interactions, once formed, are maintained throughout the duration of the trajectory. To see this figure in color, go online.