The present and future of solution NMR in investigating the structure and dynamics of channels and transporters

•Overview of successful applications of solution NMR in structural characterization of integral membrane proteins.•Comprehensive review of the advancements in the use of NMR in investigating the structure and dynamics of ion channels.•The latest NMR technology used to investigate membrane transporters.•Discussion of the future prospects of NMR in providing more dynamic views of membrane channels and transporters.•Discussion of the technical challenges to overcome. Membrane channels, transporters and receptors constitute essential means for cells to maintain homeostasis and communicate with the surroundings. Investigation of their molecular architecture and the dynamic process of transporting substrate or transmitting signals across the membrane barrier has been one of the frontiers in biomedical research. The past decade has seen numerous successes in the use of X-ray or electron crystallography in determining atomic-resolution structures of membrane proteins, and in some cases, even snapshots of different physiological states of the same protein have been obtained. But there are also many cases in which long-standing efforts to crystallize proteins have yet to succeed. Therefore we have practical needs for developing complementary biophysical tools such as NMR spectroscopy and electron microscopy for tackling these systems. This paper provides a number of key examples where the utility of solution NMR was pivotal in providing structural and functional information on ion channels and transporters.