Primary Citation of Related Structures:   9LT4, 9LTI
PubMed Abstract: 
Aerobic anoxygenic phototrophic bacteria (AAPB) are widely distributed in nature and they are important members of the marine phototrophic community. However, a structural and functional understanding of the AAPB photosynthetic apparatus is still lacking. Here, we present cryo-EM structures of the LH1-RC (core) and LH2 (peripheral) photocomplexes from the model aerobic phototroph Erythrobacter (Ery.) sanguineus. The LH1 αβ-heterodimers bind the carotenoids bacteriorubixanthinal and caloxanthin-pigments that are absent from anaerobic anoxygenic phototrophs-to form a closed ring structure. Ery. sanguineus LH1-RC contains a lipid-anchored polypeptide unrelated to any of the auxiliary proteins identified in the core complexes of purple bacteria so far. The Ery. sanguineus LH2 complex shows unique absorption characteristics, with its Q y transition being blue-shifted to 814 nm. This work provides structural insights into the unusual photosynthetic properties of AAPB and points to new avenues to further explore their biology.
Organizational Affiliation: 
Photosynthesis Research Center, State Key Laboratory of Forage Breeding-by-Design and Utilization, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Photosynthesis Research Center, State Key Laboratory of Forage Breeding-by-Design and Utilization, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
Faculty of Science, Ibaraki University, Mito 310-8512, Japan.
School of Biological Sciences, Department of Microbiology, Southern Illinois University, Carbondale, IL 62901, USA.
Photosynthesis Research Center, State Key Laboratory of Forage Breeding-by-Design and Utilization, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China; China National Botanical Garden, Beijing 100093, China; Academician Workstation of Agricultural High-Tech industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257300, China. Electronic address: longer@ibcas.ac.cn.
AB [auth F] BC [auth O] DB [auth G] DC [auth P] HB [auth Q]
AB [auth F], BC [auth O], DB [auth G], DC [auth P], HB [auth Q], LA [auth A], LB [auth I], NB [auth J], NC [auth r], OA [auth B], OC [auth r], QB [auth K], SA [auth C], VA [auth D], XB [auth N], YA [auth E]