RRC ID 86182
著者 Takahashi IY, Suzuki T, Hirooka S, Dohmae N, Miyagishima SY, Nagao R.
タイトル Comparative analysis of biochemical and sequence features of PSI-LHCI supercomplexes from Cyanidium caldarium NIES-551 and Cyanidiococcus yangmingshanensis NIES-2137.
ジャーナル Photosynth Res
Abstract Cyanidiophyceae represent basal, extremophilic taxa subdivided into several genetically distinct orders. While photosystem I supercomplexes containing light-harvesting complexes (PSI-LHCI) have been characterized in Cyanidioschyzonales and Galdieriales, their organization in Cyanidiales remains poorly understood. Here, we purified the PSI-LHCI supercomplex from Cyanidium caldarium NIES-551, and analyzed its biochemical and spectroscopic properties. SDS-PAGE and mass spectrometry identified canonical PSI and LHCI subunits. The chloroplast-encoded PSI proteins were identical to those of a previously sequenced Cd. caldarium strain. Comparative sequence analysis revealed substantial divergence in both PSI and LHCI proteins between the NIES-551 strain and Cyanidiococcus yangmingshanensis NIES-2137, a strain recently reclassified from Cd. caldarium. Pigment profiling of PSI-LHCI showed similar species across strains, yet carotenoid-to-chlorophyll a ratios were lower in NIES-551. 77-K fluorescence-emission spectra of PSI-LHCI highlighted a red-shifted emission peak in NIES-551 (734 nm) relative to NIES-2137 (727 nm), suggesting differences in pigment configuration and excitation-energy transfer. These findings indicate that PSI-LHCI in NIES-551 possesses lineage-specific pigment composition and LHCI organization. Together, these characteristics likely represent hallmarks of PSI-LHCI in Cyanidiales. Our results reinforce the evolutionary distinctiveness of Cyanidiales within Cyanidiophyceae and provide a foundation for future structural studies that will clarify the diversification of photosynthetic architecture in early-diverging red algae.
巻・号 163(5)
ページ 48
公開日 2025-9-17
DOI 10.1007/s11120-025-01169-y
PII 10.1007/s11120-025-01169-y
PMID 40960655
MeSH Carotenoids / metabolism Light-Harvesting Protein Complexes* / chemistry Light-Harvesting Protein Complexes* / genetics Light-Harvesting Protein Complexes* / metabolism Photosystem I Protein Complex* / chemistry Photosystem I Protein Complex* / genetics Photosystem I Protein Complex* / metabolism Phylogeny Rhodophyta* / genetics Rhodophyta* / metabolism
IF 3.216
リソース情報
藻類 NIES-551 NIES-2137