Q6YXQ2 · PSAC_PHYPA
- ProteinPhotosystem I iron-sulfur center
- GenepsaC
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids
- Protein existenceEvidence at protein level
- Annotation score3/5
Function
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.
Catalytic activity
- hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin] = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin]
Cofactor
Note: Binds 2 [4Fe-4S] clusters. Cluster 2 is most probably the spectroscopically characterized electron acceptor FA and cluster 1 is most probably FB.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 11 | [4Fe-4S] cluster 1 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 14 | [4Fe-4S] cluster 1 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 17 | [4Fe-4S] cluster 1 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 21 | [4Fe-4S] cluster 2 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 48 | [4Fe-4S] cluster 2 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 51 | [4Fe-4S] cluster 2 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 54 | [4Fe-4S] cluster 2 (UniProtKB | ChEBI) | ||||
Sequence: C | ||||||
Binding site | 58 | [4Fe-4S] cluster 1 (UniProtKB | ChEBI) | ||||
Sequence: C |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | chloroplast thylakoid membrane | |
Cellular Component | photosystem I | |
Molecular Function | 4 iron, 4 sulfur cluster binding | |
Molecular Function | electron transfer activity | |
Molecular Function | metal ion binding | |
Molecular Function | oxidoreductase activity | |
Biological Process | photosynthesis | |
Biological Process | photosynthetic electron transport in photosystem I |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended namePhotosystem I iron-sulfur center
- EC number
- Alternative names
Gene names
Encoded on
- Chloroplast
Organism names
- Strain
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Bryophyta > Bryophytina > Bryopsida > Funariidae > Funariales > Funariaceae > Physcomitrium
Accessions
- Primary accessionQ6YXQ2
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Plastid, chloroplast thylakoid membrane ; Peripheral membrane protein
Keywords
- Cellular component
PTM/Processing
Features
Showing features for initiator methionine, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Chain | PRO_0000061997 | 2-81 | Photosystem I iron-sulfur center | |||
Sequence: AHSVKIYDTCIGCTQCVRACPTDVLEMVPWDGCKASQIASAPRTEDCVGCKRCESACPTDFLSVRVYLGAETTRSMGLAY |
Interaction
Subunit
The eukaryotic PSI reaction center is composed of at least 11 subunits.
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 2-31 | 4Fe-4S ferredoxin-type 1 | ||||
Sequence: AHSVKIYDTCIGCTQCVRACPTDVLEMVPW | ||||||
Domain | 39-68 | 4Fe-4S ferredoxin-type 2 | ||||
Sequence: IASAPRTEDCVGCKRCESACPTDFLSVRVY |
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length81
- Mass (Da)8,772
- Last updated2007-01-23 v3
- Checksum78E6E8D3C6B317F0
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AP005672 EMBL· GenBank· DDBJ | BAC85089.1 EMBL· GenBank· DDBJ | Genomic DNA |