Proteorhodopsin phototrophy

摘要

Proteorhodopsin, a retinal-containing integral membrane pro- tein that functions as a light-driven proton pump, was discovered in the genome of an uncultivated marine bacterium; however, the prevalence, expressions and genetic variability of this protein in native marine microbial populations remain unknown. Here we report that photoactive proteorhodopsin is present in oceanic surface waters. We also provide evidence of an extensive family of globally distributed protorhodopsin variants. The protein pig- ments comprising this rhodopsin family seem to be spectrallys tuned to different habitats-absorbing light at different wave- lengths in accordance with light available in the environment.