title: Proteorhodopsin phototrophy in the ocean.
abstract: Proteorhodopsin, a retinal-containing integral membrane protein that functions as a light-driven proton pump, was discovered in the genome of an uncultivated marine bacterium; however, the prevalence, expression 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 proteorhodopsin variants. The protein pigments comprising this rhodopsin family seem to be spectrally tuned to different habitats--absorbing light at different wavelengths in accordance with light available in the environment. Together, our data suggest that proteorhodopsin-based phototrophy is a globally significant oceanic microbial process.
authors.affiliation: Monterey Bay Aquarium Research Institute, Moss Landing, California 95039, USA.
authors.forename: O
authors.initials: O
authors.lastname: Béjà
authors.forename: E N
authors.initials: EN
authors.lastname: Spudich
authors.forename: J L
authors.initials: JL
authors.lastname: Spudich
authors.forename: M
authors.initials: M
authors.lastname: Leclerc
authors.forename: E F
authors.initials: EF
authors.lastname: DeLong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry; D003001:Cloning, Molecular; D004926:Escherichia coli; D015723:Gene Library; D017404:In Situ Hybridization, Fluorescence; D008027:Light; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010933:Plankton / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012172:Retinaldehyde / Q000737:chemistry; D012243:Rhodopsin / Q000032:analysis* / Q000145:classification / Q000235:genetics; D025604:Rhodopsins, Microbial; D012623:Seawater / Q000032:analysis; D014871:Water Microbiology
chemical_list: D025604:Rhodopsins, Microbial; C413548:proteorhodopsin; D012243:Rhodopsin; D012172:Retinaldehyde