Japan Agency for Medical Research and Development (AMED)
JP21am0101118
日本
Japan Agency for Medical Research and Development (AMED)
JP21am0101116
日本
Japan Society for the Promotion of Science (JSPS)
JP16H04174
日本
Japan Society for the Promotion of Science (JSPS)
JP18H05153
日本
Japan Society for the Promotion of Science (JSPS)
20H05086
日本
Japan Society for the Promotion of Science (JSPS)
20H02856
日本
引用
ジャーナル: Nat Commun / 年: 2025 タイトル: A distinct double-ring LH1-LH2 photocomplex from an extremophilic phototroph. 著者: Kazutoshi Tani / Kenji V P Nagashima / Risa Kojima / Masaharu Kondo / Ryo Kanno / Issei Satoh / Mai Kawakami / Naho Hiwatashi / Kazuna Nakata / Sakiko Nagashima / Kazuhito Inoue / Yugo Isawa ...著者: Kazutoshi Tani / Kenji V P Nagashima / Risa Kojima / Masaharu Kondo / Ryo Kanno / Issei Satoh / Mai Kawakami / Naho Hiwatashi / Kazuna Nakata / Sakiko Nagashima / Kazuhito Inoue / Yugo Isawa / Ryoga Morishita / Shinichi Takaichi / Endang R Purba / Malgorzata Hall / Long-Jiang Yu / Michael T Madigan / Akira Mizoguchi / Bruno M Humbel / Yukihiro Kimura / Yutaka Nagasawa / Takehisa Dewa / Zheng-Yu Wang-Otomo / 要旨: Halorhodospira (Hlr.) halophila strain BN9622 is an extremely halophilic and alkaliphilic phototrophic purple sulfur bacterium isolated from a hypersaline lake in the Libyan Desert whose total ...Halorhodospira (Hlr.) halophila strain BN9622 is an extremely halophilic and alkaliphilic phototrophic purple sulfur bacterium isolated from a hypersaline lake in the Libyan Desert whose total salinity exceeded 35% at pH 10.7. Here we present a cryo-EM structure of the native LH1-LH2 co-complex from strain BN9622 at 2.22 Å resolution. Surprisingly, the LH1-LH2 co-complex consists of a double-ring cylindrical structure with the larger LH1 ring encircling a smaller LH2 ring. The Hlr. halophila LH1 contains 18 αβ-subunits and additional bacteriochlorophyll a (BChl a) molecules that absorb maximally at 797 nm. The LH2 ring is composed of 9 αβ-subunits, and the BChl a molecules in the co-complex form extensive intra- and inter-complex networks to allow near 100% efficiency of energy transfer to its surrounding LH1. The additional LH1-B797 BChls a are located in such a manner that they facilitate exciton transfer from monomeric BChls in LH2 to the dimeric BChls in LH1. The structural features of the strain BN9622 LH1-LH2 co-complex may have evolved to allow a minimal LH2 complex to maximize excitation transfer to the core complex and effectively harvest light in the physiologically demanding ecological niche of this purple bacterium.