GlpG was expressed, purified and reconstituted into liposomes (E. coli total lipid extract (Avanti Lipids)) as previously described . The protein to lipid ratio was 1:1 (w/w), corresponding to approximately 1:44 (mol/mol) and the final buffer condition for the NMR sample was 50 mM Tris-HCl, 150 mM NaCl, 1mM MgCl, pH 7.4.