9HD7
Cryo-EM structure of photosystem II C2S2M2L2 supercomplex from the green alga Chlorella ohadii
This is a non-PDB format compatible entry.
Summary for 9HD7
| Entry DOI | 10.2210/pdb9hd7/pdb |
| EMDB information | 52056 |
| Descriptor | Chlorophyll a-b binding protein Lhcbm-I, Cytochrome b559 subunit alpha, Cytochrome b559 subunit beta, ... (50 entities in total) |
| Functional Keywords | supercomplex, photosynthesis, chlorophyll, algae, membrane protein |
| Biological source | Chlorella ohadii More |
| Total number of polymer chains | 66 |
| Total formula weight | 2098239.03 |
| Authors | Kopecny, D.,Kouril, R.,Ardhad, R.,Skalidis, I.,Kastritis, P. (deposition date: 2024-11-11, release date: 2025-11-12, Last modification date: 2026-01-21) |
| Primary citation | Arshad, R.,Skalidis, I.,Kopecny, D.,Brabencova, S.,Opatikova, M.,Ilik, P.,Pospisil, P.,Hamdi, F.,Cavar Zeljkovic, S.,Kopecna, M.,Roudnicky, P.,Lazar, D.,Elias, E.,Croce, R.,Kastritis, P.L.,Kouril, R. Cryo-EM structure of photosystem II supercomplex from a green microalga with extreme phototolerance. Nat Commun, 17:341-341, 2026 Cited by PubMed Abstract: Photosystem II (PSII) is essential for energy conversion during oxygenic photosynthesis in plants and algae. Chlorella ohadii, one of the fastest multiplying green algae, thrives under the harsh desert sun but lacks the standard PSII photoprotective mechanisms involving LhcSR/PsbS proteins or protein phosphorylation. Here, we present the cryo-EM structure of the PSII supercomplex from C. ohadii at 2.9 Å resolution, which is used to determine whether the exceptional resistance to desert conditions has a structural basis in PSII. The structure reveals a distinct PsbO isoform and additional subunits, PsbR and PsbY, which enhance core complex stability through extensive interactions. Furthermore, the trimeric light-harvesting complexes (LHCII) are bound to the PSII core by specific light-harvesting proteins whose down-regulation in response to high-light conditions implies a reduction in the number of bound LHCII trimers. These structural modifications, together with the high accumulation of specific polyamines in the thylakoid membrane, play a key role in maintaining PSII stability and photoprotection, allowing C. ohadii to survive in extreme conditions. PubMed: 41513636DOI: 10.1038/s41467-025-65861-2 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.95 Å) |
Structure validation
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