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A2BT99 (PSAB_PROMS) Reviewed, UniProtKB/Swiss-Prot

Last modified May 14, 2014. Version 57. 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:A9601_17271
OrganismProchlorococcus marinus (strain AS9601) [Complete proteome] [HAMAP]
Taxonomic identifier146891 [NCBI]
Taxonomic lineageBacteriaCyanobacteriaProchloralesProchlorococcaceaeProchlorococcus

Protein attributes

Sequence length742 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 – 742742Photosystem I P700 chlorophyll a apoprotein A2 HAMAP-Rule MF_00482
PRO_0000300016

Regions

Transmembrane46 – 6924Helical; Name=I; Potential
Transmembrane135 – 15824Helical; Name=II; Potential
Transmembrane175 – 19925Helical; Name=III; Potential
Transmembrane273 – 29119Helical; Name=IV; Potential
Transmembrane336 – 35924Helical; Name=V; Potential
Transmembrane375 – 40127Helical; Name=VI; Potential
Transmembrane423 – 44523Helical; Name=VII; Potential
Transmembrane525 – 54319Helical; Name=VIII; Potential
Transmembrane583 – 60422Helical; Name=IX; Potential
Transmembrane651 – 67323Helical; Name=X; Potential
Transmembrane715 – 73521Helical; Name=XI; Potential

Sites

Metal binding5671Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding5761Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding6621Magnesium (divinyl chlorophyll-a B1 axial ligand; P700 special pair) By similarity
Metal binding6701Magnesium (divinyl chlorophyll-a B3 axial ligand) By similarity
Binding site6781Divinyl chlorophyll-a B3 By similarity
Binding site6791Phylloquinone B By similarity

Sequences

Sequence LengthMass (Da)Tools
A2BT99 [UniParc].

Last modified February 20, 2007. Version 1.
Checksum: B1F9B1238E39D3F0

FASTA74282,671
        10         20         30         40         50         60 
MATKFPSFNQ GLAQDPTTRR IWYGIATAHD FESHDGMTEE KLYQKLFSTH FGHLAIIALW 

        70         80         90        100        110        120 
VAGNLFHIAW QGNFEQFVLD PTHVRPIAHA IWDPHFGSGI TEAMTQAGAS GPVNIAYSGL 

       130        140        150        160        170        180 
YHWWYTIGMR TNEQLFQASI FMSILACWTL FAGWLHLQPK FRPSLAWFKN AESRLNHHLA 

       190        200        210        220        230        240 
VLFGFSSIAW TGHLVHVAIP ESRGQHVGWD NWLTVLPHPA GLAPFFTLNW GAYAQNPDSL 

       250        260        270        280        290        300 
DQVFGTAEGA GTAIFTFLGG LHPQSEALWL TDIAHHHIAI GTVFVIAGHM YRNTFGIGHS 

       310        320        330        340        350        360 
LKEITEAHNT RHPNDPHKGS FGINHDGIYE TVNNSLHFQL GLALASLGVA TSLVAQHMGA 

       370        380        390        400        410        420 
LPSYAFIARD YTTQSALYSH HQYIAMFLMV GAFAHGAIFF VRDYDPELNK DNVLARVLGT 

       430        440        450        460        470        480 
KEALISHLSW VTMLLGFHTL GIYVHNDVVV AFGNPEKQIL IEPVFAQFVQ AAQGKMMYGF 

       490        500        510        520        530        540 
NALLSDPTSS ASLAANSLPG NHYWMDLINR QDALSAFLPI GPADFLVHHA IALGLHTTAL 

       550        560        570        580        590        600 
ILIKGALDAR GTKLIPDKKD LGYAFPCDGP GRGGTCDSSS WDAMYLAMFW ALNLLAWVTF 

       610        620        630        640        650        660 
YWHWKHLAIW QGNVAQFNES GTYLMGWFRD YLWLNSAQLI NGYNPFGVNS LSPWAWMFLF 

       670        680        690        700        710        720 
GHLVWATGFM FLISWRGYWQ ELIETLVWAH QRTPIANLVG WRDKPVALSI VQARLVGLAH 

       730        740 
FTIGNILTFG AFVIASTSGK FG 

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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: AS9601.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
CP000551 Genomic DNA. Translation: ABM71010.1.
RefSeqYP_001010117.1. NC_008816.1.

3D structure databases

ProteinModelPortalA2BT99.
SMRA2BT99. Positions 2-741.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

STRING146891.A9601_17271.

Proteomic databases

PRIDEA2BT99.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaABM71010; ABM71010; A9601_17271.
GeneID4718458.
KEGGpmb:A9601_17271.
PATRIC22984989. VBIProMar75723_1737.

Organism-specific databases

CMRSearch...

Phylogenomic databases

eggNOGNOG04867.
HOGENOMHOG000276868.
KOK02690.
OMAAQFNESS.
OrthoDBEOG60W7PS.

Enzyme and pathway databases

BioCycPMAR146891:GH90-1759-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_PROMS
AccessionPrimary (citable) accession number: A2BT99
Entry history
Integrated into UniProtKB/Swiss-Prot: September 11, 2007
Last sequence update: February 20, 2007
Last modified: May 14, 2014
This is version 57 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