UniProt functional annotation for P0A415



	UniProt functional annotation for P0A415

UniProt code: P0A415.

Organism: Thermosynechococcus elongatus (strain BP-1).

Taxonomy: Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Thermosynechococcus.

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.

Catalytic activity: Reaction=hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin] = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin]; Xref=Rhea:RHEA:30407, Rhea:RHEA-COMP:10000, Rhea:RHEA-COMP:10001, Rhea:RHEA-COMP:10039, Rhea:RHEA-COMP:10040, ChEBI:CHEBI:29036, ChEBI:CHEBI:30212, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738, ChEBI:CHEBI:49552; EC=1.97.1.12;

Cofactor: Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883; Evidence={ECO:0000269|PubMed:11418848}; Note=Binds 2 [4Fe-4S] clusters. Cluster 2 is most probably the spectroscopically characterized electron acceptor FA and cluster 1 is most probably FB. {ECO:0000305|PubMed:11418848};

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. {ECO:0000269|PubMed:10066799, ECO:0000269|PubMed:11418848, ECO:0000269|PubMed:8901876}.

Subcellular location: Cellular thylakoid membrane {ECO:0000269|PubMed:10066799, ECO:0000269|PubMed:11418848, ECO:0000269|PubMed:8901876}; Peripheral membrane protein {ECO:0000269|PubMed:11418848}; Cytoplasmic side {ECO:0000269|PubMed:11418848}.

Annotations taken from UniProtKB at the EBI.


Organism:		Thermosynechococcus elongatus (strain BP-1).
Taxonomy:		Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Thermosynechococcus.



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.


Catalytic activity:		Reaction=hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin] = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin]; Xref=Rhea:RHEA:30407, Rhea:RHEA-COMP:10000, Rhea:RHEA-COMP:10001, Rhea:RHEA-COMP:10039, Rhea:RHEA-COMP:10040, ChEBI:CHEBI:29036, ChEBI:CHEBI:30212, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738, ChEBI:CHEBI:49552; EC=1.97.1.12;
Cofactor:		Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883; Evidence={ECO:0000269\|PubMed:11418848}; Note=Binds 2 [4Fe-4S] clusters. Cluster 2 is most probably the spectroscopically characterized electron acceptor FA and cluster 1 is most probably FB. {ECO:0000305\|PubMed:11418848};
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. {ECO:0000269\|PubMed:10066799, ECO:0000269\|PubMed:11418848, ECO:0000269\|PubMed:8901876}.
Subcellular location:		Cellular thylakoid membrane {ECO:0000269\|PubMed:10066799, ECO:0000269\|PubMed:11418848, ECO:0000269\|PubMed:8901876}; Peripheral membrane protein {ECO:0000269\|PubMed:11418848}; Cytoplasmic side {ECO:0000269\|PubMed:11418848}.