Fig. 5.

Interactions of CrgA with its environment. (A) Positioning of the transmembrane helices in a lipid bilayer. Conserved Trp side chains are shown as green sticks for carbon atoms; neighboring polar and charged side chains are shown as cyan (TM1) or pink (TM2) sticks for carbon atoms. Conserved outward-facing Gly residues are shown as magenta spheres for carbons. Lipid carbonyls are shown as ball-and-stick. In all cases, oxygen atoms are in red and nitrogen atoms are in blue. (B–E) Hydrogen bonds of Ser30, Gln52, Tyr75, and Arg91 with lipid phosphate and carbonyl groups.