O52475 (PSAB_MASLA) Reviewed, UniProtKB/Swiss-Prot
Last modified
April 3, 2013.
Version 79.
History...
Clusters with 
Names·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize orderNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize orderNames and origin
| Protein names | Recommended name: Photosystem I P700 chlorophyll a apoprotein A2 EC=1.97.1.12 Alternative name(s): PsaB | ||
| Gene names |
| ||
| Organism | Mastigocladus laminosus (Fischerella sp.) | ||
| Taxonomic identifier | 83541 [NCBI] | ||
| Taxonomic lineage | Bacteria › Cyanobacteria › Stigonematales › Mastigocladus |
Protein attributes
| Sequence length | 743 AA. |
| Sequence status | Complete. |
| Sequence processing | The displayed sequence is further processed into a mature form. |
| Protein existence | Inferred from homology |
General annotation (Comments)
| 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 By similarity. HAMAP-Rule MF_00482 |
| Catalytic activity | Reduced plastocyanin + oxidized ferredoxin + light = oxidized plastocyanin + reduced ferredoxin. HAMAP-Rule MF_00482 |
| Cofactor | 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 By similarity. |
| Subunit structure | 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 By similarity. |
| Subcellular location | Cellular thylakoid membrane; Multi-pass membrane protein By similarity HAMAP-Rule MF_00482. |
| Sequence similarities | Belongs to the PsaA/PsaB family. |
Ontologies
Sequence annotation (Features)
| Feature key | Position(s) | Length | Description | Graphical view | Feature identifier | ||||
Molecule processing | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Initiator methionine | 1 | 1 | Removed By similarity | ||||||
| Chain | 2 – 743 | 742 | Photosystem I P700 chlorophyll a apoprotein A2 HAMAP-Rule MF_00482 | PRO_0000088645 | |||||
Regions | |||||||||
| Transmembrane | 46 – 69 | 24 | Helical; Name=I; Potential | ||||||
| Transmembrane | 135 – 158 | 24 | Helical; Name=II; Potential | ||||||
| Transmembrane | 175 – 199 | 25 | Helical; Name=III; Potential | ||||||
| Transmembrane | 273 – 291 | 19 | Helical; Name=IV; Potential | ||||||
| Transmembrane | 336 – 359 | 24 | Helical; Name=V; Potential | ||||||
| Transmembrane | 375 – 401 | 27 | Helical; Name=VI; Potential | ||||||
| Transmembrane | 423 – 445 | 23 | Helical; Name=VII; Potential | ||||||
| Transmembrane | 526 – 544 | 19 | Helical; Name=VIII; Potential | ||||||
| Transmembrane | 584 – 605 | 22 | Helical; Name=IX; Potential | ||||||
| Transmembrane | 652 – 674 | 23 | Helical; Name=X; Potential | ||||||
| Transmembrane | 716 – 736 | 21 | Helical; Name=XI; Potential | ||||||
Sites | |||||||||
| Metal binding | 568 | 1 | Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity | ||||||
| Metal binding | 577 | 1 | Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity | ||||||
| Metal binding | 663 | 1 | Magnesium (chlorophyll-a B1 axial ligand; P700 special pair) By similarity | ||||||
| Metal binding | 671 | 1 | Magnesium (chlorophyll-a B3 axial ligand) By similarity | ||||||
| Binding site | 679 | 1 | Chlorophyll-a B3 By similarity | ||||||
| Binding site | 680 | 1 | Phylloquinone B By similarity | ||||||
Sequences
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References
| [1] | "Molecular cloning of the psaA and psaB genes for the core proteins of photosystem I from the thermophilic cyanobacterium Mastigocladus laminosus." Sun J., He Z.-Y., Nechushtai R., Chitnis P.R. Plant Gene Register PGR98-041 Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: PCC 7605. |
Cross-references
Sequence databases | |
|---|---|
| EMBL GenBank DDBJ | AF038558 Genomic DNA. Translation: AAC12867.1. |
3D structure databases | |
| ProteinModelPortal | O52475. |
| SMR | O52475. Positions 2-742. |
| ModBase | Search... |
Protocols and materials databases | |
| StructuralBiologyKnowledgebase | Search... |
Family and domain databases | |
| Gene3D | 1.20.1130.10. 1 hit. |
| HAMAP | MF_00482. PSI_PsaB. |
| InterPro | IPR001280. PSI_PsaA/B. IPR020586. PSI_PsaA/B_CS. IPR006244. PSI_PsaB. [Graphical view] |
| Pfam | PF00223. PsaA_PsaB. 1 hit. [Graphical view] |
| PIRSF | PIRSF002905. PSI_A. 1 hit. |
| PRINTS | PR00257. PHOTSYSPSAAB. |
| TIGRFAMs | TIGR01336. psaB. 1 hit. |
| PROSITE | PS00419. PHOTOSYSTEM_I_PSAAB. 1 hit. [Graphical view] |
| ProtoNet | Search... |
Entry information
| Entry name | PSAB_MASLA | ||||||||
| Accession | Primary (citable) accession number: O52475 | ||||||||
| Entry history |
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| Entry status | Reviewed (UniProtKB/Swiss-Prot) | ||||||||
| Annotation program | Prokaryotic Protein Annotation Program | ||||||||
Relevant documents
| SIMILARITY comments Index of protein domains and families |