| Structural highlights
6yp7 is a 24 chain structure with sequence from Pisum sativum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | Electron Microscopy, Resolution 3.8Å |
| Ligands: | , , , , , , , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
CB28_PEA The light-harvesting complex (LHC) functions as a light receptor, it captures and delivers excitation energy to photosystems with which it is closely associated.[1] May channel protons produced in the catalytic Mn center of water oxidation into the thylakoid lumen.[2]
Publication Abstract from PubMed
In plant grana thylakoid membranes Photosystem II (PSII) associates with a variable number of antenna proteins (LHCII) to form different types of supercomplexes (PSII-LHCII), whose organization is dynamically adjusted in response to light cues, with the C(2)S(2) more abundant in high-light and the C(2)S(2)M(2) in low-light. Paired PSII-LHCII supercomplexes interacting at their stromal surface from adjacent thylakoid membranes were previously suggested to mediate grana stacking. Here, we present the cryo-electron microscopy maps of paired C(2)S(2) and C(2)S(2)M(2) supercomplexes isolated from pea plants grown in high-light and low-light, respectively. These maps show a different rotational offset between the two supercomplexes in the pair, responsible for modifying their reciprocal interaction and energetic connectivity. This evidence reveals a different way by which paired PSII-LHCII supercomplexes can mediate grana stacking at diverse irradiances. Electrostatic stromal interactions between LHCII trimers almost completely overlapping in the paired C(2)S(2) can be the main determinant by which PSII-LHCII supercomplexes mediate grana stacking in plants grown in high-light, whereas the mutual interaction of stromal N-terminal loops of two facing Lhcb4 subunits in the paired C(2)S(2)M(2) can fulfil this task in plants grown in low-light. The high-light induced accumulation of the Lhcb4.3 protein in PSII-LHCII supercomplexes has been previously reported. Our cryo-electron microscopy map at 3.8 A resolution of the C(2)S(2) supercomplex isolated from plants grown in high-light suggests the presence of the Lhcb4.3 protein revealing peculiar structural features of this high-light-specific antenna important for photoprotection.
High-Light versus Low-Light: Effects on Paired Photosystem II Supercomplex Structural Rearrangement in Pea Plants.,Grinzato A, Albanese P, Marotta R, Swuec P, Saracco G, Bolognesi M, Zanotti G, Pagliano C Int J Mol Sci. 2020 Nov 16;21(22):8643. doi: 10.3390/ijms21228643. PMID:33207833[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Jahns P, Junge W. Dicyclohexylcarbodiimide-binding proteins related to the short circuit of the proton-pumping activity of photosystem II. Identified as light-harvesting chlorophyll-a/b-binding proteins. Eur J Biochem. 1990 Nov 13;193(3):731-6. PMID:2174365
- ↑ Jahns P, Junge W. Dicyclohexylcarbodiimide-binding proteins related to the short circuit of the proton-pumping activity of photosystem II. Identified as light-harvesting chlorophyll-a/b-binding proteins. Eur J Biochem. 1990 Nov 13;193(3):731-6. PMID:2174365
- ↑ Grinzato A, Albanese P, Marotta R, Swuec P, Saracco G, Bolognesi M, Zanotti G, Pagliano C. High-Light versus Low-Light: Effects on Paired Photosystem II Supercomplex Structural Rearrangement in Pea Plants. Int J Mol Sci. 2020 Nov 16;21(22):8643. PMID:33207833 doi:10.3390/ijms21228643
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