Protein Motion Guides Photosynthesis

A study of the initial stages of electron transfer in bacterial photosynthesis reinforces previously obtained evidence that photosynthetic proteins do more than simply provide the scaffolding on which to hang chromophores (Science 2007, 316, 747). Neal W. Woodbury and coworkers at Arizona State University studied the rate of the initial electron-transfer reaction in a collection of native and mutant photosynthetic reaction center proteins from a light-harvesting bacterium. By combining their data with modeling, Woodbury and coworkers conclude that slow protein motions—not simply the precise positions of chromophores—control the rate of initial electron transfer. They suggest that such dependence on protein dynamics might help explain photosynthesis' enviable efficiency.