A0A2U9NSS3 · A0A2U9NSS3_9STRA
- ProteinPhotosystem I P700 chlorophyll a apoprotein A2
- GenepsaB
- StatusUniProtKB unreviewed (TrEMBL)
- Organism
- Amino acids733 (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/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]
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 558 | [4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners | ||||
Sequence: C | ||||||
Binding site | 567 | [4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners | ||||
Sequence: C | ||||||
Binding site | 653 | Mg (UniProtKB | ChEBI) of chlorophyll a B1 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 661 | Mg (UniProtKB | ChEBI) of chlorophyll a B3 (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: M | ||||||
Binding site | 669 | chlorophyll a B3 (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 670 | phylloquinone B (UniProtKB | ChEBI) | ||||
Sequence: W |
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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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 A2
- EC number
- Alternative names
Gene names
Encoded on
- Chloroplast
Organism names
- Organism
- Taxonomic lineageEukaryota > Sar > Stramenopiles > Ochrophyta > Bacillariophyta > Mediophyceae > Biddulphiophycidae > Biddulphiales > Biddulphiaceae > Biddulphia
Accessions
- Primary accessionA0A2U9NSS3
Subcellular Location
UniProt Annotation
GO Annotation
Membrane ; Multi-pass membrane protein
Plastid, chloroplast thylakoid membrane ; Multi-pass membrane protein
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 51-70 | Helical | ||||
Sequence: FGHLAIIFLWTSGNLFHVAW | ||||||
Transmembrane | 138-156 | Helical | ||||
Sequence: SLGLLLFSCVLLIAGWLHL | ||||||
Transmembrane | 272-290 | Helical | ||||
Sequence: IAHHQLAIAVVFIIAGHMY | ||||||
Transmembrane | 333-354 | Helical | ||||
Sequence: LGLALACLGVATSLTAQHMYAL | ||||||
Transmembrane | 374-395 | Helical | ||||
Sequence: HQYIAGFLMVGAFAHGAIFFVR | ||||||
Transmembrane | 416-437 | Helical | ||||
Sequence: AIISHLSWASLFLGFHTLGLYI | ||||||
Transmembrane | 517-538 | Helical | ||||
Sequence: LVHHAIALGLHVTTLILVKGAL | ||||||
Transmembrane | 574-595 | Helical | ||||
Sequence: AFYLAMFWMLNTIGWVTFYWHW | ||||||
Transmembrane | 644-664 | Helical | ||||
Sequence: VWAWMFLFGHLIWATGFMFLI | ||||||
Transmembrane | 706-726 | Helical | ||||
Sequence: LVGLVHFAVGYILTYAAFVIA |
Keywords
- Cellular component
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
- Length733
- Mass (Da)82,093
- Last updated2018-09-12 v1
- Checksum2298C693A2467BE5