Download MendeleyThe structure of PSI-LHCI from Cyanidium caldarium provides evolutionary insights into conservation and diversity of red-lineage LHCs.
Kato, K., Hamaguchi, T., Kumazawa, M., Nakajima, Y., Ifuku, K., Hirooka, S., Hirose, Y., Miyagishima, S.Y., Suzuki, T., Kawakami, K., Dohmae, N., Yonekura, K., Shen, J.R., Nagao, R.(2024) Proc Natl Acad Sci U S A 121: e2319658121-e2319658121
- PubMed: 38442179
- DOI: https://doi.org/10.1073/pnas.2319658121
- Primary Citation of Related Structures:
8WEY - PubMed Abstract:
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-Å 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.
Organizational Affiliation:
Division of Photosynthesis and Structural Biology, Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
