Solid-state NMR [13C,15N] resonance assignments of the nucleotide-Binding Domain of a bacterial Cyclic Nucleotide-Gated Channel

Channels regulated by cyclic nucleotides are key signalling proteins in several biological pathways. The regulatory aspect is conferred by a C-terminal cyclic nucleotide-binding domain (CNBD). We report resonance assignments of the CNBD of a bacterial mlCNG channel obtained using 2D and 3D solid-state NMR under Magicangle Spinning conditions. A secondary chemical shift analysis of the 141 residue protein suggests a threedimensional fold seen in earlier X-ray and solution-state NMR work and points to spectroscopic polymorphism for a selected set of resonances.