FIG. 3.

(A) Cartoon depiction of the proposed orientation in membranes of the subgroup 3 bacteriocin curvacin A. The N-terminal β-sheet-like region and the central polar helix are both positioned in the interface region of the membrane, whereas the hinge region with Gly28 as the central residue enables the C-terminal hydrophobic helix to penetrate into the hydrophobic core of the membrane. (B) Position of the central helix in the membrane viewed down the helical axis, with Ala22 positioned close to the hydrophobic part of the membrane. (C) The C-terminal helix viewed down the helical axis. The GxxxG-like motif created by Gly33, Gly37, and Gly40 (with Gly29 positioned between Gly40 and Gly33), forming a putative site for helix-helix interactions with a membrane-embedded receptor protein, is circled.