FIGURE 1.

Quaternary structure of MscS. (A) Side view of the MscS heptamer shown in ribbons representation with one subunit marked in black. Transmembrane helices TM1, TM2, and TM3 are indicated. (B) The left panel presents the side view of the cross section of MscS shown in a surface representation. The box indicates the gate region formed by the TM3 helices. A-A marks the cross section through the cytoplasmic chamber of the channel, and the cross section is shown in the right panel. Sizes of the bottom (left panel) and of the side (right panel) openings are indicated. Sizes of PEGs used are shown as shaded spheres.