Proteorhodopsin phototrophy in the ocean.
O Béjà1, E N Spudich, J L Spudich
1Monterey Bay Aquarium Research Institute, Moss Landing, California 95039, USA.
Nature
|July 19, 2001
Summary
Photoactive proteorhodopsin is prevalent in oceanic surface waters, with a diverse family of variants globally distributed. These proteorhodopsins are spectrally tuned to their environments, indicating a significant role in oceanic microbial phototrophy.
Area of Science:
- Microbiology
- Biochemistry
- Oceanography
Background:
- Proteorhodopsin, a light-driven proton pump, was initially found in uncultivated marine bacteria.
- Its prevalence, expression, and genetic diversity in natural marine populations were previously unknown.
Purpose of the Study:
- To investigate the presence and distribution of photoactive proteorhodopsin in oceanic surface waters.
- To identify the genetic variability and spectral tuning of proteorhodopsin variants in marine environments.
Main Methods:
- Environmental DNA sequencing to detect proteorhodopsin genes.
- Spectroscopic analysis to determine light absorption properties of proteorhodopsin variants.
Main Results:
- Photoactive proteorhodopsin is widespread in oceanic surface waters.
- An extensive family of globally distributed proteorhodopsin variants was identified.
- These variants exhibit spectral tuning, absorbing light at wavelengths matching ambient environmental light.
Conclusions:
- Proteorhodopsin-based phototrophy is a globally significant process in marine microbial ecosystems.
- The spectral diversity of proteorhodopsins suggests adaptation to various oceanic habitats.
- This finding expands our understanding of microbial energy acquisition in the ocean.
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