Open AccessDarwinian adaptation of proteorhodopsin to different light intensities in the marine environment
Author(s) -
Joseph P. Bielawski,
Katherine A. Dunn,
Gazalah Sabehi,
Oded Béjà
Publication year - 2004
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0403999101
Subject(s) - adaptation (eye) , darwinism , selection (genetic algorithm) , retinal , evolutionary biology , biology , computational biology , artificial intelligence , computer science , neuroscience , biochemistry
Proteorhodopsin, a retinal-binding protein, represents a potentially significant source of light-driven energy production in the world's oceans. The distribution of photochemically divergent proteorhodopsins is stratified according to depth. Here, we present evidence that such photochemical diversity was tuned by Darwinian selection. By using a Bayesian method, we identified sites targeted by Darwinian selection and mapped them to three-dimensional models of proteorhodopsins. We suggest that spectral fine-tuning results from the combined effect of amino acids that directly interact with retinal and those that influence the confirmation of the retinal-binding pocket.