Four complete turns of a curved 3₁₀-helix at atomic resolution: the crystal structure of the peptaibol trichovirin I-4A in a polar environment suggests a transition to α-helix for membrane function

The first structure of a subfamily 4 peptaibol antibiotic, trichovirin I-4A, is described at atomic resolution. The structure suggests a conformational transition to obtain the necessary amphiphilicity for membrane insertion and water/ion transport across the hydrophobic barrier.