HAMAP

Accession	MF_01303
Dates	6-JUN-2002 (Created) 10-OCT-2011 (Last updated, Version 43)

Data class

Protein

Predictors

HAMAP; MF_01303; [distribution of match scores in UniProtKB];[seed alignment for MF_01303]

Names

PSI_PsaC

Identifier

PSAC

Protein name

RecName: Full=Photosystem I iron-sulfur center; EC=1.97.1.12; AltName: Full=9 kDa polypeptide; AltName: Full=PSI-C; AltName: Full=Photosystem I subunit VII; AltName: Full=PsaC;

Gene name

psaC

FUNCTION: 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/cytochrome c6-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).

FUNCTION: 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).

CATALYTIC ACTIVITY: Reduced plastocyanin + oxidized ferredoxin + light = oxidized plastocyanin + reduced ferredoxin.

COFACTOR: Binds 2 4Fe-4S clusters. Cluster 2 is most probably the spectroscopically characterized electron acceptor FA and cluster 1 is most probably FB (By similarity).

SUBUNIT: The eukaryotic PSI reaction center is composed of at least 11 subunits (By similarity).

SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane; Peripheral membrane protein; Stromal side (By similarity).

SUBUNIT: The cyanobacterial PSI reaction center is composed of one copy each of psaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes (By similarity).

SUBCELLULAR LOCATION: Cell inner membrane; Peripheral membrane protein; Cytoplasmic side (By similarity).

SUBUNIT: The cyanobacterial PSI reaction center is composed of one copy each of psaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes (By similarity).

SUBCELLULAR LOCATION: Cellular thylakoid membrane; Peripheral membrane protein; Cytoplasmic side (By similarity).

Pfam	PF00037; Fer4; 2;
PRINTS	PR00353; 4FE4SFRDOXIN; 2;
PROSITE	PS00198; 4FE4S_FER_1; 2; PS51379; 4FE4S_FER_2; 2; trigger=PRU00711;

4Fe-4S, Electron transport, Iron, Iron-sulfur, Membrane, Metal-binding, Photosynthesis, Photosystem I, Repeat, Transport, Oxidoreductase.

Cell membrane, Cell inner membrane.

Thylakoid.

GO:0009055; Molecular function: electron carrier activity.
GO:0015979; Biological process: photosynthesis.
GO:0055114; Biological process: oxidation-reduction process.

GO:0009535; Cellular component: chloroplast thylakoid membrane.

GO:0005886; Cellular component: plasma membrane.

GO:0042651; Cellular component: thylakoid membrane.

From: PSAC_THEEB (P0A415)
Key		From		To		Description		Condition		FTGroup
METAL		11		11		Iron-sulfur 1 (4Fe-4S) (By similarity)		C
METAL		14		14		Iron-sulfur 1 (4Fe-4S) (By similarity)		C
METAL		17		17		Iron-sulfur 1 (4Fe-4S) (By similarity)		C
METAL		21		21		Iron-sulfur 2 (4Fe-4S) (By similarity)		C
METAL		48		48		Iron-sulfur 2 (4Fe-4S) (By similarity)		C
METAL		51		51		Iron-sulfur 2 (4Fe-4S) (By similarity)		C
METAL		54		54		Iron-sulfur 2 (4Fe-4S) (By similarity)		C
METAL		58		58		Iron-sulfur 1 (4Fe-4S) (By similarity)		C

Size range:	81-93 amino acids
Related UniRules:	None
Template:	Q00914 (PSAC_CHLRE); P0A411 (PSAC_ANAVT); P0A415 (PSAC_THEEB); P0A416 (PSAC_SYNEN); P31087 (PSAC_SYNP2); P31085 (PSAC_SYNP6); P32422 (PSAC_SYNY3): [Recover all]
Scope:	Bacteria; Cyanobacteria Plastid
Fusion:	Nter: None; Cter: None
Duplicate:	None
Plasmid encoded:	None