Fig. S4.

Model of CD16A assembled with CD247 dimer. The previously reported solution NMR structure of human CD247 dimer (PDB ID code 2HAC) was assembled with a helical model of the human CD16A TM sequence in a 60-ns REMD simulation in a model lipid bilayer as described in Materials and Methods. The major cluster contained 800/1,000 randomly chosen models with an average rmsd of 1.58 Å compared with the centroid structure shown here. In the ribbon diagram shown in A, CD247 is colored green, and CD16A is colored orange. Key residues are shown as sticks, with residue type and number labeled. Interface residues also identified in the CD16A mutagenesis are colored purple. (B) Rotated view of the structure in A, with CD247 shown as an electrostatic surface. (C) “Front” view of the solution NMR structure of CD247 dimer alone for comparison. Key residues are shown as sticks. (D) A view down the long axis of the CD247 dimer (Top) and CD247-CD16A trimer (Bottom) highlighting the rearrangement of the Y12-T17 hydrogen-bond network to accommodate new contact to CD16A. Colored as in A.