Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Bacterial rhodopsin: evidence for a new type of phototrophy in the sea.

Science (New York, N.Y.) | Sep 15, 2000

Extremely halophilic archaea contain retinal-binding integral membrane proteins called bacteriorhodopsins that function as light-driven proton pumps. So far, bacteriorhodopsins capable of generating a chemiosmotic membrane potential in response to light have been demonstrated only in halophilic archaea. We describe here a type of rhodopsin derived from bacteria that was discovered through genomic analyses of naturally occuring marine bacterioplankton. The bacterial rhodopsin was encoded in the genome of an uncultivated gamma-proteobacterium and shared highest amino acid sequence similarity with archaeal rhodopsins. The protein was functionally expressed in Escherichia coli and bound retinal to form an active, light-driven proton pump. The new rhodopsin exhibited a photochemical reaction cycle with intermediates and kinetics characteristic of archaeal proton-pumping rhodopsins. Our results demonstrate that archaeal-like rhodopsins are broadly distributed among different taxa, including members of the domain Bacteria. Our data also indicate that a previously unsuspected mode of bacterially mediated light-driven energy generation may commonly occur in oceanic surface waters worldwide.

Pubmed ID: 10988064 RIS Download

Mesh terms: Aerobiosis | Amino Acid Sequence | Archaea | Bacteria | Bacterial Physiological Phenomena | Cloning, Molecular | Escherichia coli | Gammaproteobacteria | Molecular Sequence Data | Oceans and Seas | Photochemistry | Photosynthesis | Phylogeny | Phytoplankton | Protein Binding | Proton Pumps | Retinaldehyde | Rhodopsin | Rhodopsins, Microbial | Water Microbiology