2017 Volume 57 Issue 4 Pages 179-185
The microbial rhodopsins are a class of membrane proteins with seven transmembrane helices harboring an all-trans retinal retinal chromophore. The functions of microbial rhodopsins are diverse, including light-driven cation and anion pumps, light-gated cation and anion channels, positive and negative phototaxis sensors, photochromic sensors, and light-activated enzymes. Here I focus on the ion-transporting rhodopsins and explain the mechanism of the pumps and the channels revealed by the electrophysiological studies. Characteristics of light-gated cation channel (channelrhodopsins) and proton-pumping rhodopsins are discussed.
