Probing Secondary, Tertiary, and Quaternary Structure along with Protein−Cofactor Interactions for a Helical Transmembrane Protein Complex through <sup>1</sup>H Spin Diffusion with MAS NMR Spectroscopy

Structure determination of membrane proteins with magic angle spinning NMR is rapidly developing. Probing secondary, tertiary, and quaternary structure along with protein−cofactor interactions through <sup>1</sup>H spin diffusion with MAS NMR is demonstrated for a helical transmembrane model protein complex.