2wsc

Structural highlights

Function

[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] [CAB6_ARATH] The light-harvesting complex (LHC) functions as a light receptor, it captures and delivers excitation energy to photosystems with which it is closely associated. [PSAI_PEA] May help in the organization of the PsaL subunit. [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). [PSAE1_ARATH] Stabilizes the interaction between PsaC and the PSI core, assists the docking of the ferredoxin to PSI and interacts with ferredoxin-NADP oxidoreductase (By similarity). [PSAH_SPIOL] Possible role could be the docking of the LHC I antenna complex to the core complex. [PSAJ_SPIOL] May help in the organization of the PsaE and PsaF subunits. [PSAD_SPIOL] PsaD can form complexes with ferredoxin and ferredoxin-oxidoreductase in photosystem I (PS I) reaction center. PSAD may encode the ferredoxin-docking protein. [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.^[1] May channel protons produced in the catalytic Mn center of water oxidation into the thylakoid lumen.^[2] [PSAF_SPIOL] Probably participates in efficiency of electron transfer from plastocyanin to P700 (or cytochrome c553 in algae and cyanobacteria). This plastocyanin-docking protein contributes to the specific association of plastocyanin to PSI. [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.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

• Photosystem I

References

1. ↑ 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
2. ↑ 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
3. ↑ Amunts A, Toporik H, Borovikova A, Nelson N. Structure determination and improved model of plant photosystem I. J Biol Chem. 2010 Jan 29;285(5):3478-86. Epub 2009 Nov 18. PMID:19923216 doi:10.1074/jbc.M109.072645