The structure of PSI- LHCI from Cyanidium caldarium provides evolutionary insights into conservation and diversity of red- lineage LHCs

• 成果类型: Article
• 署名作者: Kato, Koji; Hamaguchi, Tasuku; Kumazawa, Minoru; Nakajima, Yoshiki; Ifuku, Kentaro; Hirooka, Shunsuke; Hirose, Yuu; Miyagishima, Shin-ya; Suzuki, Takehiro; Kawakami, Keisuke; Dohmae, Naoshi; Yonekura, Koji; Shen, Jian- Ren; Nagao, Ryo
• 署名单位: Okayama University; Okayama University; Tohoku University; RIKEN; Kyoto University; Research Organization of Information & Systems (ROIS); National Institute of Genetics (NIG) - Japan; Toyohashi University of Technology; Graduate University for Advanced Studies - Japan; RIKEN; Shizuoka University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11187
• DOI: 10.1073/pnas.2319658121
• 发表日期: 2024-03-12
• 关键词: sequence; genome

摘要

Light- harvesting complexes (LHCs) are diversified among photosynthetic organisms, and the structure of the photosystem I-LHC (PSI-LHCI) supercomplex has been shown to be variable depending on the species of organisms. However, the structural and evolutionary correlations of red- lineage LHCs are unknown. Here, we determined a 1.92- & Aring; resolution cryoelectron microscopic structure of a PSI-LHCI supercomplex isolated from the red alga Cyanidium caldarium RK - 1 (NIES- 2137), which is an important taxon in the Cyanidiophyceae. We subsequently investigated the correlations of PSI-LHCIs from different organisms through structural comparisons and phylogenetic analysis. The PSI-LHCI structure obtained shows five LHCI subunits surrounding a PSI- monomer core. The five LHCIs are composed of two Lhcr1s, two Lhcr2s, and one Lhcr3. Phylogenetic analysis of LHCs bound to PSI in the red- lineage algae showed clear orthology of LHCs between C. caldarium and Cyanidioschyzon merolae, whereas no orthologous relationships were found between C. caldarium Lhcr1-3 and LHCs in other red- lineage PSI-LHCI structures. These findings provide evolutionary insights into conservation and diversity of red- lineage LHCs associated with PSI.