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A2CC72 (PSAB_PROM3) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 54. 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:P9303_23471
OrganismProchlorococcus marinus (strain MIT 9303) [Complete proteome] [HAMAP]
Taxonomic identifier59922 [NCBI]
Taxonomic lineageBacteriaCyanobacteriaProchloralesProchlorococcaceaeProchlorococcus

Protein attributes

Sequence length749 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 divinyl chlorophyll a, 1 divinyl chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core antenna: 90 divinyl chlorophyll a, 22 carotenoids, 3 phospholipids and 1 galactolipid. P700 is a divinyl chlorophyll a/divinyl chlorophyll a' dimer, A0 is one or more divinyl 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 divinyl 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 – 749749Photosystem I P700 chlorophyll a apoprotein A2 HAMAP-Rule MF_00482
PRO_0000300018

Regions

Transmembrane46 – 6924Helical; Name=I; Potential
Transmembrane135 – 15824Helical; Name=II; Potential
Transmembrane175 – 19925Helical; Name=III; Potential
Transmembrane273 – 29119Helical; Name=IV; Potential
Transmembrane343 – 36624Helical; Name=V; Potential
Transmembrane382 – 40827Helical; Name=VI; Potential
Transmembrane430 – 45223Helical; Name=VII; Potential
Transmembrane532 – 55019Helical; Name=VIII; Potential
Transmembrane590 – 61122Helical; Name=IX; Potential
Transmembrane658 – 68023Helical; Name=X; Potential
Transmembrane722 – 74221Helical; Name=XI; Potential

Sites

Metal binding5741Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding5831Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding6691Magnesium (divinyl chlorophyll-a B1 axial ligand; P700 special pair) By similarity
Metal binding6771Magnesium (divinyl chlorophyll-a B3 axial ligand) By similarity
Binding site6851Divinyl chlorophyll-a B3 By similarity
Binding site6861Phylloquinone B By similarity

Sequences

Sequence LengthMass (Da)Tools
A2CC72 [UniParc].

Last modified February 20, 2007. Version 1.
Checksum: 6C0AE61033501E0C

FASTA74983,151
        10         20         30         40         50         60 
MATKFPSFSQ GLAQDPTTRR IWYGIATAHD FESHDGMTEE RLYQKLFSTH FGHLAVIGLW 

        70         80         90        100        110        120 
VAGNLFHIAW QGNFEQWVAD PQNVQPIAHA IWDPHFGQGI SDALTQAGAS RPVNICYSGL 

       130        140        150        160        170        180 
YHWWYTIGMR TNTELYQGAI FIDILVAWLL FGGWLHLQPK FRPSLAWFKN AEAMMNHHLA 

       190        200        210        220        230        240 
VLFGFTNIAW TGHLVHVAIP ESRGQHVGWD NFLTVLPHPE GLTPFFTGNW GAYAQNPDSL 

       250        260        270        280        290        300 
NHAFGTSEGA GTAILTFLGG VHPQSGALWL TDISHHHIAI GVFMIIGGHM YRNSFGIGHT 

       310        320        330        340        350        360 
FKEITDGHNT SHPNDPHKDG FREKIGHYGL SHTGITDTIN NSLHFQLGLA LACLGTAASL 

       370        380        390        400        410        420 
VAHHMGALPS YAFIAQDYTT QAALYTHHQY IAIFLMCGAF SHGAIFFVRD YDPEANKDNV 

       430        440        450        460        470        480 
LARVLETKEA LISHLSWVCM LLGFHTLALY LHNDVVIAFG TPEKQILVEP IFAQFIQAAS 

       490        500        510        520        530        540 
GKVMYGLDVL LANANSAPSL AAAGMPGDHY WMDLINASPE VSNFMPIGPG DFLVHHGIAL 

       550        560        570        580        590        600 
GLHTTALILI KGALDARGSK LMPDKKDFGY AFACDGPGRG GTCDISAWDS TYMAIFWALN 

       610        620        630        640        650        660 
TIAWATYYWH WKHLAAWQGN MAQFNESSTH LMGWFRDYLW INSSQIINGY NPFGINNLSP 

       670        680        690        700        710        720 
WAYMFLAGHL VWATGFMFLI SWRGYWQELI ETLVWAHQRS PIANLVGWRD KPVALSIVQA 

       730        740 
RLVGVTHFAV GNIFTFGAFV IASTASKFG 

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References

[1]"Patterns and implications of gene gain and loss in the evolution of Prochlorococcus."
Kettler G.C., Martiny A.C., Huang K., Zucker J., Coleman M.L., Rodrigue S., Chen F., Lapidus A., Ferriera S., Johnson J., Steglich C., Church G.M., Richardson P., Chisholm S.W.
PLoS Genet. 3:2515-2528(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: MIT 9303.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
CP000554 Genomic DNA. Translation: ABM79082.1.
RefSeqYP_001018347.1. NC_008820.1.

3D structure databases

ProteinModelPortalA2CC72.
SMRA2CC72. Positions 2-748.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

STRING59922.P9303_23471.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaABM79082; ABM79082; P9303_23471.
GeneID4778124.
KEGGpmf:P9303_23471.
PATRIC23002255. VBIProMar17757_2418.

Organism-specific databases

CMRSearch...

Phylogenomic databases

eggNOGNOG04867.
HOGENOMHOG000276868.
KOK02690.
OMAAQFNESS.
OrthoDBEOG60W7PS.
ProtClustDBPRK13199.

Enzyme and pathway databases

BioCycPMAR59922:GH54-2455-MONOMER.

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.
SUPFAMSSF81558. SSF81558. 1 hit.
TIGRFAMsTIGR01336. psaB. 1 hit.
PROSITEPS00419. PHOTOSYSTEM_I_PSAAB. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry namePSAB_PROM3
AccessionPrimary (citable) accession number: A2CC72
Entry history
Integrated into UniProtKB/Swiss-Prot: September 11, 2007
Last sequence update: February 20, 2007
Last modified: April 16, 2014
This is version 54 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