Fig. 6. Difference Fourier map contoured at -3s (red) and +3s (blue) viewed from the top as in Fig. 1B. The Ca trace of GlpG and the side chain of His-150 are also shown.

Fig. 7. Superposition of the closed (cyan) and open (magenta) structures (top view). The dotted lines indicate major side-chain movements. The two structures were superimposed based on Ca positions of five transmembrane helices (S1-S4 and S6). S5 was omitted because we wanted to detect any potential shift of this helix (see Discussion in the main text).

Fig. 8. Comparison of the electron density features from the side (back view). The 2F_o - F_c maps are contoured at 1.5s levels. (Upper) Closed state where L5 is clearly visible (yellow labels). (Lower) open-cap conformation. With electron density features for Phe-245 and Met-247 missing, residues in the active site become exposed to the lipid (red labels). Some secondary structural elements in GlpG are also labeled (blue parentheses).

Fig. 9. Thermal motions in GlpG. Yellow and red correspond to protein regions with the highest temperature factor, whereas the blue regions have lower values. This illustration corresponds to the back view. The disordered L5 region is indicated by the yellow dots.