7ew6 | pdb_00007ew6
Barley photosystem I-LHCI-Lhca5 supercomplex
Structural highlights
FunctionPSAA_HORVU PsaA and PsaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX. PSI is a plastocyanin-ferredoxin oxidoreductase, converting photonic excitation into a charge separation, which transfers an electron from the donor P700 chlorophyll pair to the spectroscopically characterized acceptors A0, A1, FX, FA and FB in turn. Oxidized P700 is reduced on the lumenal side of the thylakoid membrane by plastocyanin. Publication Abstract from PubMedThe chloroplast NADH dehydrogenase-like (NDH) complex is composed of at least 29 subunits and has an important role in mediating photosystem I (PSI) cyclic electron transport (CET)(1-3). The NDH complex associates with PSI to form the PSI-NDH supercomplex and fulfil its function. Here, we report cryo-electron microscopy structures of a PSI-NDH supercomplex from barley (Hordeum vulgare). The structures reveal that PSI-NDH is composed of two copies of the PSI-light-harvesting complex I (LHCI) subcomplex and one NDH complex. Two monomeric LHCI proteins, Lhca5 and Lhca6, mediate the binding of two PSI complexes to NDH. Ten plant chloroplast-specific NDH subunits are presented and their exact positions as well as their interactions with other subunits in NDH are elucidated. In all, this study provides a structural basis for further investigations on the functions and regulation of PSI-NDH-dependent CET. Architecture of the chloroplast PSI-NDH supercomplex in Hordeum vulgare.,Shen L, Tang K, Wang W, Wang C, Wu H, Mao Z, An S, Chang S, Kuang T, Shen JR, Han G, Zhang X Nature. 2022 Jan;601(7894):649-654. doi: 10.1038/s41586-021-04277-6. Epub 2021 , Dec 8. PMID:34879391[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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