8ow6

PERIDININ-CHLOROPHYLL-PROTEIN OF HETEROCAPSA PYGMAEA, 100K

spinqualitylabelsall models 8ow6, resolution 1.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 8ow6 is a 4 chain structure with sequence from Heterocapsa pygmaea. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.2Å Ligands: CL, CLA, HYP, K, PID, PO4, W4O Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Light harvesting proteins are optimized to efficiently collect and transfer light energy for photosynthesis. In eukaryotic dinoflagellates these complexes utilize chlorophylls and a special carotenoid, peridinin, and arrange them for efficient excitation energy transfer. At the same time, the carotenoids protect the system by quenching harmful chlorophyll triplet states. Here we use advanced spectroscopic techniques and X-ray structure analysis to investigate excitation energy transfer processes in the major soluble antenna, the peridinin chlorophyll a protein (PCP) from the free living dinoflagellate Heterocapsa pygmaea. We determined the 3D-structure of this complex at high resolution (1.2 A). For better comparison, we improved the reference structure of this protein from Amphidinium carterae to a resolution of 1.15 A. We then used fs and ns time-resolved absorption spectroscopy to study the mechanisms of light harvesting, but also of the photoprotective quenching of the chlorophyll triplet state. The photoprotection site was further characterized by Electron Spin Echo Envelope Modulation (ESEEM) spectroscopy to yield information on water molecules involved in triplet-triplet energy transfer. Similar to other PCP complexes, excitation energy transfer from peridinin to chlorophyll is found to be very efficient, with transfer times in the range of 1.6-2.1 ps. One of the four carotenoids, the peridinin 614, is well positioned to quench the chlorophyll triplet state with high efficiency and transfer times in the range of tens of picoseconds. Our structural and dynamic data further support, that the intrinsic water molecule coordinating the chlorophyll Mg ion plays an essential role in photoprotection. Structural and spectroscopic characterization of the peridinin-chlorophyll a-protein (PCP) complex from Heterocapsa pygmaea (HPPCP).,Schulte T, Magdaong NCM, Di Valentin M, Agostini A, Tait CE, Niedzwiedzki DM, Carbonera D, Hofmann E Biochim Biophys Acta Bioenerg. 2024 Sep 24;1866(1):149510. doi: , 10.1016/j.bbabio.2024.149510. PMID:39321862 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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