Structure of the light‐driven sodium pump KR2 and its implications for optogenetics

A key and common process present in organisms from all domains of life is the maintenance of the ion gradient between the inside and the outside of the cell. The gradient is generated by various active transporters, among which are the light-driven ion pumps of the microbial rhodopsin family. Whereas the proton-pumping and anion-pumping rhodopsins have been known for a long time, the cation (sodium) pumps were described only recently. Following...