Q8S8X4 · PSAA_ATRBE
- ProteinPhotosystem I P700 chlorophyll a apoprotein A1
- GenepsaA
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids750 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
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-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.
Catalytic activity
- reduced [plastocyanin] + hnu + oxidized [2Fe-2S]-[ferredoxin] = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin]
Cofactor
Note: 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 | 573 | [4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners | ||||
Sequence: C | ||||||
Binding site | 582 | [4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners | ||||
Sequence: C | ||||||
Binding site | 675 | Mg (UniProtKB | ChEBI) of chlorophyll a' A1 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 683 | Mg (UniProtKB | ChEBI) of chlorophyll a A3 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: M | ||||||
Binding site | 691 | chlorophyll a A3 (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 692 | phylloquinone A (UniProtKB | ChEBI) | ||||
Sequence: W |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | chloroplast thylakoid membrane | |
Cellular Component | photosystem I | |
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
Encoded on
- Chloroplast
Organism names
- Strain
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > asterids > lamiids > Solanales > Solanaceae > Solanoideae > Hyoscyameae > Atropa
Accessions
- Primary accessionQ8S8X4
Subcellular Location
UniProt Annotation
GO Annotation
Plastid, chloroplast thylakoid membrane ; Multi-pass membrane protein
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 70-93 | Helical; Name=I | ||||
Sequence: VFSAHFGQLSIIFLWLSGMYFHGA | ||||||
Transmembrane | 156-179 | Helical; Name=II | ||||
Sequence: LYCTAIGALVFAALMLFAGWFHYH | ||||||
Transmembrane | 195-219 | Helical; Name=III | ||||
Sequence: LNHHLAGLLGLGSLSWAGHQVHVSL | ||||||
Transmembrane | 291-309 | Helical; Name=IV | ||||
Sequence: IAHHHLAIAILFLIAGHMY | ||||||
Transmembrane | 346-369 | Helical; Name=V | ||||
Sequence: WHAQLSLNLAMLGSLTIVVAHHMY | ||||||
Transmembrane | 385-411 | Helical; Name=VI | ||||
Sequence: LSLFTHHMWIGGFLIVGAAAHAAIFMV | ||||||
Transmembrane | 433-455 | Helical; Name=VII | ||||
Sequence: AIISHLNWACIFLGFHSFGLYIH | ||||||
Transmembrane | 531-549 | Helical; Name=VIII | ||||
Sequence: FLVHHIHAFTIHVTVLILL | ||||||
Transmembrane | 589-610 | Helical; Name=IX | ||||
Sequence: HVFLGLFWMYNAISVVIFHFSW | ||||||
Transmembrane | 664-686 | Helical; Name=X | ||||
Sequence: LSAYGLFFLGAHFVWAFSLMFLF | ||||||
Transmembrane | 724-744 | Helical; Name=XI | ||||
Sequence: AVGVTHYLLGGIATTWAFFLA |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000088536 | 1-750 | Photosystem I P700 chlorophyll a apoprotein A1 | |||
Sequence: MIIRSPEPEVKILVDRDPVKTSFEEWARPGHFSRTIAKGPDTTTWIWNLHADAHDFDSHTSDLEEISRKVFSAHFGQLSIIFLWLSGMYFHGARFSNYEAWLSDPTHIGPSAQVVWPIVGQEILNGDVRGGFRGIQITSGFFQIWRASGITSELQLYCTAIGALVFAALMLFAGWFHYHKAAPKLAWFQDVESMLNHHLAGLLGLGSLSWAGHQVHVSLPINQFLNAGVDPKEIPLPHEYILNRDLLAQLYPSFAEGATPFFTLNWSKYADFLTFRGGLDPVTGGLWLTDIAHHHLAIAILFLIAGHMYRTNWGIGHGLKDILEAHKGPFTGQGHKGLYEILTTSWHAQLSLNLAMLGSLTIVVAHHMYSMPPYPYLATDYGTQLSLFTHHMWIGGFLIVGAAAHAAIFMVRDYDPTTRYNDLLDRVLRHRDAIISHLNWACIFLGFHSFGLYIHNDTMSALGRPQDMFSDTAIQLQPVFAQWIQNTHALAPGATAPGATASTSLTWGGGDLVAVGGKVALLPIPLGTADFLVHHIHAFTIHVTVLILLKGVLFARSSRLIPDKANLGFRFPCDGPERGGTCQVSAWDHVFLGLFWMYNAISVVIFHFSWKMQSDVWGSVSDQGVVTHITGGNFAQSSITINGWLRDFLWAQASQVIQSYGSSLSAYGLFFLGAHFVWAFSLMFLFSGRGYWQELIESIVWAHNKLKVAPATQPRALSIIQGRAVGVTHYLLGGIATTWAFFLARIITVG |
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 eukaryotic PSI reaction center is composed of at least 11 subunits.
Structure
Sequence
- Sequence statusComplete
- Length750
- Mass (Da)83,249
- Last updated2002-06-01 v1
- ChecksumA9BF289F59798E68
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AJ316582 EMBL· GenBank· DDBJ | CAC88044.1 EMBL· GenBank· DDBJ | Genomic DNA |