O96804 · PSAC_SKECO
- ProteinPhotosystem I iron-sulfur center
- GenepsaC
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids
- Protein existenceInferred from homology
- Annotation score4/5
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/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
- 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 | 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 > Sar > Stramenopiles > Ochrophyta > Bacillariophyta > Coscinodiscophyceae > Thalassiosirophycidae > Thalassiosirales > Skeletonemataceae > Skeletonema
Accessions
- Primary accessionO96804
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_0000062004 | 2-81 | Photosystem I iron-sulfur center | |||
Sequence: SHTVKIYDTCIGCTQCVRACPTDVLEMVPWDGCKSGQIASSPRVEDCVGCKRCETACPTDFLSVRVYLGAETTRSLGLAY |
Interaction
Subunit
The eukaryotic PSI reaction center is composed of at least 11 subunits.
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 2-31 | 4Fe-4S ferredoxin-type 1 | ||||
Sequence: SHTVKIYDTCIGCTQCVRACPTDVLEMVPW | ||||||
Domain | 37-68 | 4Fe-4S ferredoxin-type 2 | ||||
Sequence: GQIASSPRVEDCVGCKRCETACPTDFLSVRVY |
Keywords
- Domain
Family and domain databases
Sequence
- Sequence statusComplete
- Length81
- Mass (Da)8,798
- Last updated2007-01-23 v3
- Checksum0B3E4CEB35F50C9B