Structural highlights
4y28 is a 16 chain structure with sequence from Pisum sativum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , , , , , , , , , , , , |
| Activity: | Photosystem I, with EC number 1.97.1.12 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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Function
[PSAB_PEA] 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 (By similarity). [PSAA_PEA] 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. [CB23_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] [PSAI_PEA] May help in the organization of the PsaL subunit. [CB24_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.[3] May channel protons produced in the catalytic Mn center of water oxidation into the thylakoid lumen.[4] [PSAC_PEA] Apoprotein for the two 4Fe-4S centers FA and FB of photosystem I (PSI); essential for photochemical activity. FB is the terminal electron acceptor of PSI, donating electrons to ferredoxin. The C-terminus interacts with PsaA/B/D and helps assemble the protein into the PSI complex. Required for binding of PsaD and PsaE to PSI. 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 (By similarity).[HAMAP-Rule:MF_01303] [D5MAL3_PEA] May help in the organization of the PsaE and PsaF subunits.[HAMAP-Rule:MF_00522]
Publication Abstract from PubMed
Most life forms on Earth are supported by solar energy harnessed by oxygenic photosynthesis. In eukaryotes, photosynthesis is achieved by large membrane-embedded super-complexes, containing reaction centers and connected antennae. Here, we report the structure of the higher plant PSI-LHCI super-complex determined at 2.8 A resolution. The structure includes 16 subunits and more than 200 prosthetic groups, which are mostly light harvesting pigments. The complete structures of the four LhcA subunits of LHCI include 52 chlorophyll a and 9 chlorophyll b molecules, as well as 10 carotenoids and 4 lipids. The structure of PSI-LHCI includes detailed protein pigments and pigment-pigment interactions, essential for the mechanism of excitation energy transfer and its modulation in one of nature's most efficient photochemical machines.
The structure of plant photosystem I super-complex at 2.8 A resolution.,Mazor Y, Borovikova A, Nelson N Elife. 2015 Jun 15;4:e07433. doi: 10.7554/eLife.07433. PMID:26076232[5]
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
- ↑ 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
- ↑ Mazor Y, Borovikova A, Nelson N. The structure of plant photosystem I super-complex at 2.8 A resolution. Elife. 2015 Jun 15;4:e07433. doi: 10.7554/eLife.07433. PMID:26076232 doi:http://dx.doi.org/10.7554/eLife.07433
