4xk8

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] [PSAI_PEA] May help in the organization of the PsaL subunit. [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] [PSAJ_PHAVU] May help in the organization of the PsaE and PsaF subunits.

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. ↑ Qin X, Suga M, Kuang T, Shen JR. Photosynthesis. Structural basis for energy transfer pathways in the plant PSI-LHCI supercomplex. Science. 2015 May 29;348(6238):989-95. doi: 10.1126/science.aab0214. PMID:26023133 doi:http://dx.doi.org/10.1126/science.aab0214