Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Cryo-EM structure of a plant photosystem II supercomplex with light-harvesting protein Lhcb8 and α-tocopherol
Δημιουργός/Συγγραφέας:	Opatíková, Monika Semchonok, Dmitry A Kopečný, David Ilík, Petr Pospíšil, Pavel Ilíková, Iva Roudnický, Pavel Zeljković, Sanja Ćavar Tarkowski, Petr Kyrilis, Fotis L Hamdi, Farzad [EL] Καστρίτης, Παναγιώτης[EN] Kastritis, Panagiotis Kouřil, Roman
Ημερομηνία:	2023-08
Γλώσσα:	Αγγλικά
ISSN:	2055-0278
DOI:	10.1038/s41477-023-01483-0
Άλλο:	37550369
Περίληψη:	The heart of oxygenic photosynthesis is the water-splitting photosystem II (PSII), which forms supercomplexes with a variable amount of peripheral trimeric light-harvesting complexes (LHCII). Our knowledge of the structure of green plant PSII supercomplex is based on findings obtained from several representatives of green algae and flowering plants; however, data from a non-flowering plant are currently missing. Here we report a cryo-electron microscopy structure of PSII supercomplex from spruce, a representative of non-flowering land plants, at 2.8 Å resolution. Compared with flowering plants, PSII supercomplex in spruce contains an additional Ycf12 subunit, Lhcb4 protein is replaced by Lhcb8, and trimeric LHCII is present as a homotrimer of Lhcb1. Unexpectedly, we have found α-tocopherol (α-Toc)/α-tocopherolquinone (α-TQ) at the boundary between the LHCII trimer and the inner antenna CP43. The molecule of α-Toc/α-TQ is located close to chlorophyll a614 of one of the Lhcb1 proteins and its chromanol/quinone head is exposed to the thylakoid lumen. The position of α-Toc in PSII supercomplex makes it an ideal candidate for the sensor of excessive light, as α-Toc can be oxidized to α-TQ by high-light-induced singlet oxygen at low lumenal pH. The molecule of α-TQ appears to shift slightly into the PSII supercomplex, which could trigger important structure-functional modifications in PSII supercomplex. Inspection of the previously reported cryo-electron microscopy maps of PSII supercomplexes indicates that α-Toc/α-TQ can be present at the same site also in PSII supercomplexes from flowering plants, but its identification in the previous studies has been hindered by insufficient resolution.
Τίτλος πηγής δημοσίευσης:	Nature plants
Τόμος/Κεφάλαιο:	9
Τεύχος:	8
Σελίδες:	1359–1369
Θεματική Κατηγορία:	[EL] Φυσιολογία φυτών[EN] Plant physiology [EL] Εφαρμοσμένη οπτική. Φωτονική[EN] Applied optics. Photonics [EL] Βιοχημεία[EN] Biochemistry
Λέξεις-Κλειδιά:	Cryoelectron Microscopy Thylakoids Photosynthesis Plants Photosystem II Protein Complex alpha-Tocopherol
EU Grant:	Plants as a tool for sustainable global development BMBF, ZIK programme hot4cryo Saxony-Anhalt Sustainable systems and technologies, improving crop production for higher quality of production of food, feed, and raw materials, under conditions of changing climate UP CIISB
EU Grant identifier:	21-05497S CZ.02.1.01/0.0/0.0/16_019/0000827 03Z22HN23 03Z22HI2 03COV04 101086665 ZS/2016/04/78115 391498659 RTG 2467 RO0423 LM2023042 CZ.02.1.01/0.0/0.0/18_046/0015974
Κάτοχος πνευματικών δικαιωμάτων:	© 2023, The Author(s), under exclusive licence to Springer Nature Limited.
Ηλεκτρονική διεύθυνση στον εκδότη (link):	https://doi.org/10.1038/s41477-023-01483-0
Εμφανίζεται στις συλλογές:	Ινστιτούτο Χημικής Βιολογίας - Επιστημονικό έργο