Antibiotic resistance is pathogenic bacteria is a major clinical problem. Resistance to all antibiotiotic classes, currentl yin clinical use, has been reported. By contrast, the class of lanthionine antibiotics remians active against clinical isolated of S. aureus, C. difficile and other Gram-positives, which are tolerant to conventional therapies. Their mode of action relies on a unique target, with which they form transmembrane pores. We propose a study of such antibiotic/target pores to obtain the size and shape of the complex and provide scaffolding for building a molecular model; we will investigate the axial extension of the pore using reflectivity techniques and SANS, as well as its lateral dimension using SANS and off-specilar reflectivity measurements. Protonated complexes will be studied in deuterated lipid bilayers. The deuterated lipid will be contrast-matched.