Enough sunlight hits the Earth to power the planet many times over—if energy capture were more efficient. Thus, scientists have looked at nature’s means to understand photosynthesis in a sun-loving, soil-dwelling bacterium. A team of scientists has gained a fundamental understanding of the inner workings of this vital process and how it differs among plant systems. Their discovery may provide a new template for beginning organic-based solar panel design (i.e., “artificial leaves”) or possibly renewable biofuel applications.
But the team’s structural biologists are capturing freeze-frame images of crystallized proteins throughout the whole process of the simplest form of photosynthesis, in the single-celled heliobacteria, which are fundamentally different than plants. Instead of using water like plants, for example, heliobacteria use hydrogen sulfide and grow without oxygen; after photosynthesis, they give off the foul-smelling sulfur gas in place of oxygen. The scientists grew the “perfect” X-ray diffracting crystal charge after many initial trials. In this breakthrough study, they found an almost perfect symmetry in the heliobacter RC, which helps it gather every available photon of near-infrared light to build chlorophylls.
Gisriel, C., et al. “Structure of a symmetric photosynthetic reaction center–photosystem,” Science 357(6355), 1021–1025 (2017). [DOI:10.1126/science.aan5611].
Instruments and Facilities Used: X-ray macromolecular crystallograpy at Biodesign Center for Applied Structural Discovery at Arizona State University. Advanced Light Source at Berkeley Center for Structural Biology at Lawrence Berkeley National Laboratory. Structural Biology Center–CAT beamline of the Advanced Photon Source at Argonne National Laboratory.
Funding Acknowledgements: Funded by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (OBES), U.S. Department of Energy (DOE) Office of Science, through grant DE-SC0010575 to K.E.R., R.F., and J.H.G.; supported with x-ray crystallographic equipment and infrastructure provided by P. Fromme of the Biodesign Center for Applied Structural Discovery at Arizona State University. Berkeley Center for Structural Biology supported in part by the National Institutes of Health’s (NIH) National Institute of General Medical Sciences (NIGMS) and the Howard Hughes Medical Institute (HHMI). The Advanced Light Source (ALS) is a DOE Scientific User Facility (SUF) supported by the Director, OBES, DOE Office of Science, and operated for DOE Office of Science by Lawrence Berkeley National Laboratory (LBNL). Results derived from work performed at Argonne National Laboratory’s (ANL) Structural Biology Center (SBC) at the Advanced Photon Source (APS). SBC funded by the Office of Biological and Environmental Research (BER), DOE Office of Science. ANL is operated by University of Chicago Argonne, LLC, for the DOE Office of Science under contract DE-AC02-06CH11357.