Expression, refolding, and initial structural characterization of the Y. pestis Ail outer membrane protein in lipids

►Y. pestis Ail outer membrane protein is expressed and purified in high yields. ►Y. pestis Ail is refolded quantitatively in lipid micelles, bicelles, and bilayers. ►Y. pestis Ail yields high-quality solution and solid-state NMR spectra in these environments. ►NMR studies show that Y. pestis Ail adopts a well-defined transmembrane β-sheet structure.