Primary Citation of Related Structures:   7COY
PubMed Abstract: 
Acaryochloris marina is one of the cyanobacterial species that can use far-red light to drive photochemical reactions for oxygenic photosynthesis. Here, we report the structure of A. marina photosystem I (PSI) reaction center, determined by cryo-electron microscopy at 2.58 Å resolution. The structure reveals an arrangement of electron carriers and light-harvesting pigments distinct from other type I reaction centers. The paired chlorophyll, or special pair (also referred to as P740 in this case), is a dimer of chlorophyll d and its epimer chlorophyll d'. The primary electron acceptor is pheophytin a, a metal-less chlorin. We show the architecture of this PSI reaction center is composed of 11 subunits and we identify key components that help explain how the low energy yield from far-red light is efficiently utilized for driving oxygenic photosynthesis.
Organizational Affiliation: 
Biostructural Mechanism Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo, Japan.
Research Center for Artificial Photosynthesis (ReCAP), Osaka City University, Sumiyoshi-ku, Osaka, Japan. kawakami.k@spring8.or.jp.
Biostructural Mechanism Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo, Japan. kawakami.k@spring8.or.jp.
Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo, Japan.
Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan.
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, Japan.
Laboratory of Supramolecular Crystallography, Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
Biostructural Mechanism Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo, Japan. yone@spring8.or.jp.
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Sendai, Japan. yone@spring8.or.jp.
Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo, Japan. kashino@sci.u-hyogo.ac.jp.