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Q9R6T9 (PSAB_SYNPW) Reviewed, UniProtKB/Swiss-Prot

Last modified May 1, 2013. Version 85. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
Photosystem I P700 chlorophyll a apoprotein A2
EC=1.97.1.12
Alternative name(s):
PsaB
Gene names
Name:psaB
Ordered Locus Names:SynWH7803_0392
OrganismSynechococcus sp. (strain WH7803) [Complete proteome] [HAMAP]
Taxonomic identifier32051 [NCBI]
Taxonomic lineageBacteria › Cyanobacteria › Oscillatoriophycideae › Chroococcales › Synechococcus

Protein attributes

Sequence length738 AA.
Sequence statusComplete.
Protein existenceInferred 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.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 738738Photosystem I P700 chlorophyll a apoprotein A2 HAMAP-Rule MF_00482
PRO_0000088656

Regions

Transmembrane46 – 6924Helical; Name=I; Potential
Transmembrane135 – 15824Helical; Name=II; Potential
Transmembrane175 – 19925Helical; Name=III; Potential
Transmembrane273 – 29119Helical; Name=IV; Potential
Transmembrane333 – 35624Helical; Name=V; Potential
Transmembrane372 – 39827Helical; Name=VI; Potential
Transmembrane420 – 44223Helical; Name=VII; Potential
Transmembrane521 – 53919Helical; Name=VIII; Potential
Transmembrane579 – 60022Helical; Name=IX; Potential
Transmembrane647 – 66923Helical; Name=X; Potential
Transmembrane711 – 73121Helical; Name=XI; Potential

Sites

Metal binding5631Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding5721Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding6581Magnesium (chlorophyll-a B1 axial ligand; P700 special pair) By similarity
Metal binding6661Magnesium (chlorophyll-a B3 axial ligand) By similarity
Binding site6741Chlorophyll-a B3 By similarity
Binding site6751Phylloquinone B By similarity

Sequences

Sequence LengthMass (Da)Tools
Q9R6T9 [UniParc].

Last modified May 1, 2000. Version 1.
Checksum: B47FEE66CE669ACF

FASTA73881,818
        10         20         30         40         50         60 
MATKFPSFSQ GLAQDPTTRR IWYGIATAHD FESHDGMTEE KLYQKLFSTH FGHLAIIGLW 

        70         80         90        100        110        120 
VSGNLFHIAW QGNFEQWVAD PLHVRPIAHA IWDPHFGQGA IDAFTQAGAS SPVNIAYSGL 

       130        140        150        160        170        180 
YHWFYTIGMT TNAELYQGSI FMMILSAWAL FAGWLHLQPK FRPSLAWFKN AESRLNHHLA 

       190        200        210        220        230        240 
VLFGFSSIAW TGHLVHVAIP ESRGQHVGWD NFLNVMPHPA GLGPFFTGNW GVYAQNPDTM 

       250        260        270        280        290        300 
GQVFGSAEGS GTAILTFLGG FHPQTEALWL TDIAHHHLAI GVIFVIAGHM YRTNFGIGHS 

       310        320        330        340        350        360 
IREILEAHNP PQGTPGDLGA GHKGLYDTIN NSLHFQLGLA LASLGVVTSL VAQHMYAMPS 

       370        380        390        400        410        420 
YAFIAKDYTT QAALYTHHQY IAIFLMCGAF AHGAIFFIRD YDPEANKDNV LARMLEHKEA 

       430        440        450        460        470        480 
IISHLSWVSL FLGFHTLGLY VHNDVVVAFG TPEKQILVEP VFAQFVQAAS GKAIYGFDVL 

       490        500        510        520        530        540 
LANTGGVAAN ANAAYMGGWM DAINGVRGSN DLFLPIGPGD FLVHHAIALG LHTTTLILVK 

       550        560        570        580        590        600 
GALDARGSKL MPDKKDFGYS FPCDGPGRGG TCDISAWDAF YLAVFWALNT VGWVTFYWHW 

       610        620        630        640        650        660 
KHLAIWQGNV AQFNESSTYL MGWFRDYLWL NSSQLINGYN PFGSNNLAVW AWMFLFGHLV 

       670        680        690        700        710        720 
WATGFMFLIS WRGYWQELIE TIVWAHQRTP LANLVGWRDK PVALSIVQAR VVGLAHFTIG 

       730 
YILTYAAFLI ASTSGKFG

« Hide

References

« Hide 'large scale' references
[1]"Rapid evolutionary divergence of photosystem I core subunits PsaA and PsaB in the marine prokaryote Prochlorococcus."
van der Staay G.W.M., Moon-van der Staay S.Y., Garczarek L., Partensky F.
Photosyn. Res. 65:131-139(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]Genoscope
Submitted (MAY-2006) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: WH7803.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		AJ133190 Genomic DNA. Translation: CAB64209.1.
CT971583 Genomic DNA. Translation: CAK22818.1.
RefSeqYP_001224115.1. NC_009481.1.

3D structure databases

ProteinModelPortalQ9R6T9.
SMRQ9R6T9. Positions 2-737.
ModBaseSearch...

Protein-protein interaction databases

STRING32051.SynWH7803_0392.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaCAK22818; CAK22818; SynWH7803_0392.
GeneID5146319.
KEGGsyx:SynWH7803_0392.
PATRIC23826838. VBISynSp43824_0397.

Organism-specific databases

CMRSearch...

Phylogenomic databases

eggNOGNOG04867.
HOGENOMHOG000276868.
KOK02690.
OMAAQFNESS.
ProtClustDBPRK13199.

Family and domain databases

Gene3D1.20.1130.10. 1 hit.
HAMAPMF_00482. PSI_PsaB.
InterProIPR001280. PSI_PsaA/B.
IPR020586. PSI_PsaA/B_CS.
IPR006244. PSI_PsaB.
[Graphical view]
PfamPF00223. PsaA_PsaB. 1 hit.
[Graphical view]
PIRSFPIRSF002905. PSI_A. 1 hit.
PRINTSPR00257. PHOTSYSPSAAB.
TIGRFAMsTIGR01336. psaB. 1 hit.
PROSITEPS00419. PHOTOSYSTEM_I_PSAAB. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry namePSAB_SYNPW
AccessionPrimary (citable) accession number: Q9R6T9
Secondary accession number(s): A5GIQ3
Entry history
Integrated into UniProtKB/Swiss-Prot: November 16, 2001
Last sequence update: May 1, 2000
Last modified: May 1, 2013
This is version 85 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

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