9I1R
Structure of the bicylindrical allophycocyanin core expressed during far-red light photoacclimation (FaRLiP)
Summary for 9I1R
| Entry DOI | 10.2210/pdb9i1r/pdb |
| EMDB information | 52573 |
| Descriptor | Phycocyanin, Allophycocyanin beta subunit apoprotein, Allophycocyanin beta-18 subunit apoprotein, ... (9 entities in total) |
| Functional Keywords | phycobilisome, allophycocyanin, complex, photosynthesis |
| Biological source | Chroococcidiopsis thermalis PCC 7203 More |
| Total number of polymer chains | 50 |
| Total formula weight | 1045219.69 |
| Authors | Consoli, G.,Leong, H.F.,Davis, G.A.,Richardson, T.,McInnes, A.,Murray, J.W.,Fantuzzi, A.,Rutherford, A.W. (deposition date: 2025-01-16, release date: 2025-07-02) |
| Primary citation | Consoli, G.,Leong, H.F.,Davis, G.A.,Richardson, T.,McInnes, A.,Murray, J.W.,Fantuzzi, A.,Rutherford, A.W. Structure of a stripped-down and tuned-up far-red phycobilisome. Commun Biol, 8:907-907, 2025 Cited by PubMed Abstract: A diverse subset of cyanobacteria can transiently modify their photosynthetic machinery during far-red light photoacclimation to drive photosynthesis with less energetic photons (700 nm-800 nm). To achieve this, all the main light-driven components of the photosynthetic apparatus, including their allophycocyanin antenna, are replaced with red-shifted paralogues. Recent studies based on the structure of an incomplete complex provided some insights into the tuning of the far-red phycobiliproteins. Here, we solved the structure of the intact bicylindrical allophycocyanin complex from the cyanobacterium Chroococcidiopsis thermalis PCC 7203 at a resolution of 2.51 Å determined by Cryo-electron microscopy single particle analysis. A comparison between conserved structural features in far-red and white light allophycocyanin cores provides insight on the evolutionary adaptations needed to optimize excitation energy transfer in the far-red light adapted photosynthetic apparatus. The reduction in antenna size in far-red photosynthesis suggests a need to optimize membrane packing to increase the number of photosystems and tune the ratio between chlorophyll f molecules and bilin pigments, while the wider spread in the absorption range of the bilins suggests faster and more efficient excitation energy transfer to far-red Photosystem II by limiting backflow of excitation from the reaction centres to the far-red bilin pigments. PubMed: 40494956DOI: 10.1038/s42003-025-08326-y PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.51 Å) |
Structure validation
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