Structural highlights
7qrm is a 16 chain structure with sequence from Spinacia oleracea. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
CYB6_SPIOL Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions.[HAMAP-Rule:MF_00633]
Publication Abstract from PubMed
Plants use solar energy to power cellular metabolism. The oxidation of plastoquinol and reduction of plastocyanin by cytochrome b(6)f (Cyt b(6)f) is known as one of the key steps of photosynthesis, but the catalytic mechanism in the plastoquinone oxidation site (Q(p)) remains elusive. Here, we describe two high-resolution cryo-EM structures of the spinach Cyt b(6)f homodimer with endogenous plastoquinones and in complex with plastocyanin. Three plastoquinones are visible and line up one after another head to tail near Q(p) in both monomers, indicating the existence of a channel in each monomer. Therefore, quinones appear to flow through Cyt b(6)f in one direction, transiently exposing the redox-active ring of quinone during catalysis. Our work proposes an unprecedented one-way traffic model that explains efficient quinol oxidation during photosynthesis and respiration.
High-resolution cryo-EM structures of plant cytochrome b(6)f at work.,Sarewicz M, Szwalec M, Pintscher S, Indyka P, Rawski M, Pietras R, Mielecki B, Koziej L, Jaciuk M, Glatt S, Osyczka A Sci Adv. 2023 Jan 13;9(2):eadd9688. doi: 10.1126/sciadv.add9688. Epub 2023 Jan , 13. PMID:36638176[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Sarewicz M, Szwalec M, Pintscher S, Indyka P, Rawski M, Pietras R, Mielecki B, Koziej L, Jaciuk M, Glatt S, Osyczka A. High-resolution cryo-EM structures of plant cytochrome b(6)f at work. Sci Adv. 2023 Jan 13;9(2):eadd9688. doi: 10.1126/sciadv.add9688. Epub 2023 Jan , 13. PMID:36638176 doi:http://dx.doi.org/10.1126/sciadv.add9688
