P0A405 · PSAA_THEVB
- ProteinPhotosystem I P700 chlorophyll a apoprotein A1
- GenepsaA
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids755 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
Function
function
PsaA and PsaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX. 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. Oxidized P700 is reduced on the lumenal side of the thylakoid membrane by plastocyanin or cytochrome c6.
Catalytic activity
- hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin] = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin]
Cofactor
Note: PSI electron transfer chain: 5 chlorophyll a, 1 chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core antenna: 90 chlorophyll a, 22 carotenoids, 3 phospholipids and 1 galactolipid. P700 is a chlorophyll a/chlorophyll a' dimer, A0 is one or more chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe-4S iron-sulfur center.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 578 | [4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners | ||||
Sequence: C | ||||||
Binding site | 587 | [4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners | ||||
Sequence: C | ||||||
Binding site | 680 | Mg (UniProtKB | ChEBI) of chlorophyll a' A1 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 688 | Mg (UniProtKB | ChEBI) of chlorophyll a A3 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: M | ||||||
Binding site | 696 | chlorophyll a A3 (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 697 | phylloquinone A (UniProtKB | ChEBI) | ||||
Sequence: W |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | photosystem I | |
Cellular Component | plasma membrane-derived thylakoid membrane | |
Molecular Function | 4 iron, 4 sulfur cluster binding | |
Molecular Function | chlorophyll binding | |
Molecular Function | electron transfer activity | |
Molecular Function | magnesium ion binding | |
Molecular Function | oxidoreductase activity | |
Biological Process | photosynthesis |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended namePhotosystem I P700 chlorophyll a apoprotein A1
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Cyanobacteriota > Cyanophyceae > Acaryochloridales > Thermosynechococcaceae > Thermosynechococcus
Accessions
- Primary accessionP0A405
- Secondary accessions
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Cellular thylakoid membrane ; Multi-pass membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-64 | Cytoplasmic | ||||
Sequence: MTISPPEREPKVRVVVDNDPVPTSFEKWAKPGHFDRTLARGPQTTTWIWNLHALAHDFDTHTSD | ||||||
Transmembrane | 65-96 | Helical; Name=I | ||||
Sequence: LEDISRKIFSAHFGHLAVVFIWLSGMYFHGAK | ||||||
Topological domain | 97-155 | Lumenal, thylakoid | ||||
Sequence: FSNYEAWLADPTGIKPSAQVVWPIVGQGILNGDVGGGFHGIQITSGLFQLWRASGITNE | ||||||
Transmembrane | 156-179 | Helical; Name=II | ||||
Sequence: FQLYCTAIGGLVMAGLMLFAGWFH | ||||||
Topological domain | 180-192 | Cytoplasmic | ||||
Sequence: YHKRAPKLEWFQN | ||||||
Transmembrane | 193-217 | Helical; Name=III | ||||
Sequence: VESMLNHHLAGLLGLGSLAWAGHQI | ||||||
Topological domain | 218-293 | Lumenal, thylakoid | ||||
Sequence: HVSLPINKLLDAGVAAKDIPLPHEFILNPSLMAELYPKVDWGFFSGVIPFFTFNWAAYSDFLTFNGGLNPVTGGLW | ||||||
Transmembrane | 294-311 | Helical; Name=IV | ||||
Sequence: LSDTAHHHLAIAVLFIIA | ||||||
Topological domain | 312-352 | Cytoplasmic | ||||
Sequence: GHMYRTNWGIGHSLKEILEAHKGPFTGAGHKGLYEVLTTSW | ||||||
Transmembrane | 353-376 | Helical; Name=V | ||||
Sequence: HAQLAINLAMMGSLSIIVAQHMYA | ||||||
Topological domain | 377-386 | Lumenal, thylakoid | ||||
Sequence: MPPYPYLATD | ||||||
Transmembrane | 387-418 | Helical; Name=VI | ||||
Sequence: YPTQLSLFTHHMWIGGFLVVGGAAHGAIFMVR | ||||||
Topological domain | 419-436 | Cytoplasmic | ||||
Sequence: DYDPAMNQNNVLDRVLRH | ||||||
Transmembrane | 437-468 | Helical; Name=VII | ||||
Sequence: RDAIISHLNWVCIFLGFHSFGLYVHNDTMRAF | ||||||
Topological domain | 469-532 | Lumenal, thylakoid | ||||
Sequence: GRPQDMFSDTGIQLQPVFAQWVQNLHTLAPGGTAPNAAATASVAFGGDVVAVGGKVAMMPIVLG | ||||||
Transmembrane | 533-558 | Helical; Name=VIII | ||||
Sequence: TADFMVHHIHAFTIHVTVLILLKGVL | ||||||
Topological domain | 559-590 | Cytoplasmic | ||||
Sequence: FARSSRLIPDKANLGFRFPCDGPGRGGTCQVS | ||||||
Transmembrane | 591-619 | Helical; Name=IX | ||||
Sequence: GWDHVFLGLFWMYNCISVVIFHFSWKMQS | ||||||
Topological domain | 620-668 | Lumenal, thylakoid | ||||
Sequence: DVWGTVAPDGTVSHITGGNFAQSAITINGWLRDFLWAQASQVIGSYGSA | ||||||
Transmembrane | 669-690 | Helical; Name=X | ||||
Sequence: LSAYGLLFLGAHFIWAFSLMFL | ||||||
Topological domain | 691-723 | Cytoplasmic | ||||
Sequence: FSGRGYWQELIESIVWAHNKLKVAPAIQPRALS | ||||||
Transmembrane | 724-753 | Helical; Name=XI | ||||
Sequence: IIQGRAVGVAHYLLGGIATTWAFFLARIIS |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000088591 | 1-755 | Photosystem I P700 chlorophyll a apoprotein A1 | |||
Sequence: MTISPPEREPKVRVVVDNDPVPTSFEKWAKPGHFDRTLARGPQTTTWIWNLHALAHDFDTHTSDLEDISRKIFSAHFGHLAVVFIWLSGMYFHGAKFSNYEAWLADPTGIKPSAQVVWPIVGQGILNGDVGGGFHGIQITSGLFQLWRASGITNEFQLYCTAIGGLVMAGLMLFAGWFHYHKRAPKLEWFQNVESMLNHHLAGLLGLGSLAWAGHQIHVSLPINKLLDAGVAAKDIPLPHEFILNPSLMAELYPKVDWGFFSGVIPFFTFNWAAYSDFLTFNGGLNPVTGGLWLSDTAHHHLAIAVLFIIAGHMYRTNWGIGHSLKEILEAHKGPFTGAGHKGLYEVLTTSWHAQLAINLAMMGSLSIIVAQHMYAMPPYPYLATDYPTQLSLFTHHMWIGGFLVVGGAAHGAIFMVRDYDPAMNQNNVLDRVLRHRDAIISHLNWVCIFLGFHSFGLYVHNDTMRAFGRPQDMFSDTGIQLQPVFAQWVQNLHTLAPGGTAPNAAATASVAFGGDVVAVGGKVAMMPIVLGTADFMVHHIHAFTIHVTVLILLKGVLFARSSRLIPDKANLGFRFPCDGPGRGGTCQVSGWDHVFLGLFWMYNCISVVIFHFSWKMQSDVWGTVAPDGTVSHITGGNFAQSAITINGWLRDFLWAQASQVIGSYGSALSAYGLLFLGAHFIWAFSLMFLFSGRGYWQELIESIVWAHNKLKVAPAIQPRALSIIQGRAVGVAHYLLGGIATTWAFFLARIISVG |
Interaction
Subunit
The PsaA/B heterodimer binds the P700 chlorophyll special pair and subsequent electron acceptors. PSI consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. 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.
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length755
- Mass (Da)83,183
- Last updated2005-03-15 v1
- Checksum36A39CCE5D119AEA
Sequence caution
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
BA000039 EMBL· GenBank· DDBJ | BAC08282.1 EMBL· GenBank· DDBJ | Genomic DNA | Different initiation |