Abstract
The structure of the transmembrane domain of bacterial potassium channel KcsA has been extensively characterized, yet little information is available on the structure of its cytosolic N- and C-termini. This study presents high-resolution magic angle spinning (HR-MAS) and fractional deuteration as tools to study these poorly resolved regions for proteoliposome-embedded KcsA. Using 1H-detected HR-MAS NMR, we show that the C-terminus transitions from a rigid structure to a more dynamic structure as the solution is rendered acidic. We make previously unreported assignments of residues in the C-terminus of lipid embedded channels. Further, we also show evidence for hydrolysis of lipid head groups in proteoliposome samples during typical experimental timeframes.
Competing Interest Statement
The authors have declared no competing interest.
