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Q20EW7 (PSAB_OLTVI) Reviewed, UniProtKB/Swiss-Prot

Last modified April 3, 2013. Version 38. 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):
PSI-B
PsaB
Gene names
Name:psaB
Encoded onPlastid; Chloroplast
OrganismOltmannsiellopsis viridis (Marine flagellate)
Taxonomic identifier51324 [NCBI]
Taxonomic lineageEukaryota › Viridiplantae › Chlorophyta › Oltmannsiellopsis

Protein attributes

Sequence length734 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

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 eukaryotic PSI reaction center is composed of at least 11 subunits By similarity.

Subcellular location

Plastid › chloroplast thylakoid membrane; Multi-pass membrane protein HAMAP-Rule MF_00482.

Sequence similarities

Belongs to the PsaA/PsaB family.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 734734Photosystem I P700 chlorophyll a apoprotein A2 HAMAP-Rule MF_00482
PRO_0000277124

Regions

Transmembrane46 – 6924Helical; Name=I; Potential
Transmembrane135 – 15824Helical; Name=II; Potential
Transmembrane175 – 19925Helical; Name=III; Potential
Transmembrane273 – 29119Helical; Name=IV; Potential
Transmembrane330 – 35324Helical; Name=V; Potential
Transmembrane369 – 39527Helical; Name=VI; Potential
Transmembrane417 – 43923Helical; Name=VII; Potential
Transmembrane517 – 53519Helical; Name=VIII; Potential
Transmembrane575 – 59622Helical; Name=IX; Potential
Transmembrane643 – 66523Helical; Name=X; Potential
Transmembrane707 – 72721Helical; Name=XI; Potential

Sites

Metal binding5591Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding5681Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding6541Magnesium (chlorophyll-a B1 axial ligand; P700 special pair) By similarity
Metal binding6621Magnesium (chlorophyll-a B3 axial ligand) By similarity
Binding site6701Chlorophyll-a B3 By similarity
Binding site6711Phylloquinone B By similarity

Sequences

Sequence LengthMass (Da)Tools
Q20EW7 [UniParc].

Last modified April 18, 2006. Version 1.
Checksum: 3C172D215EEBBD45

FASTA73481,590
        10         20         30         40         50         60 
MATKFPKFSQ GLAQDPTTRR IWFGIATAHD FESHDGMTEE NLYQKIFASH FGQLAIIFLW 

        70         80         90        100        110        120 
TSGNLFHVAW QGNFEQWIKD PLHIRPIAHA IWDPHFGQPA VEAFTRGGAS GPVNIATSGV 

       130        140        150        160        170        180 
YQWWYTIGMR TNQELYTASV FLSLMAGVFL FAGWLHLQPK FQPSLSWFKN AESRLNHHLS 

       190        200        210        220        230        240 
GLFGVSSLAW TGHLVHVAIP AARGQRVGWD NFLTTLPHPE GLTPFFTGNW AAYAANPDSA 

       250        260        270        280        290        300 
NHIFGTSAGA GTAILTFLGG FHPQTQSLWL TDIAHHHLAI AVVFIIAGHQ YRTNFGIGHS 

       310        320        330        340        350        360 
MREILDAHTP PAGGLGAGHK GLFDTVNNSL HFQLGLALAS VGTICSMVAQ HIYSLPPYAF 

       370        380        390        400        410        420 
LAQDYTAQAA LYTHHQYIAG FIMCGAFAHG AIFFIRDYDP EQNKGNVLAR ILDHKEAIIS 

       430        440        450        460        470        480 
HLSWVSLFLG FHTLGLYVHN DVMQAFGTPE KQILIEPVFA QWIQAAQGKA LYGFDFLLSS 

       490        500        510        520        530        540 
SASPAYSASQ SVWLPGWLDA INSNNNSLFL TIGPGDFLVH HAIALGLHTT TLILVKGALD 

       550        560        570        580        590        600 
ARGSKLMPDK KDFGYSFPCD GPGRGGTCDI SAWDAFYLAV FWMLNTIGWV TFYFHWKHLG 

       610        620        630        640        650        660 
IWQGNVSQFN ESSTYLMGWL RDYLWLNSSQ LINGYNPNGM NSLGVWSWAF LLAHLIYATG 

       670        680        690        700        710        720 
FMFLISWRGY WQELIETLVW SHERTPLASL VRWRDKPVAL SIVQARLVGL VHFSVGYVLT 

       730 
YGSFLIASTS SKFG

« Hide

References

[1]"The complete chloroplast DNA sequence of the green alga Oltmannsiellopsis viridis reveals a distinctive quadripartite architecture in the chloroplast genome of early diverging ulvophytes."
Pombert J.-F., Lemieux C., Turmel M.
BMC Biol. 4:3-3(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		DQ291132 Genomic DNA. Translation: ABB81946.1.
RefSeqYP_635878.1. NC_008099.1.

3D structure databases

ProteinModelPortalQ20EW7.
SMRQ20EW7. Positions 2-733.
ModBaseSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

GeneID4100125.

Phylogenomic databases

ProtClustDBCHL00054.

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_OLTVI
AccessionPrimary (citable) accession number: Q20EW7
Entry history
Integrated into UniProtKB/Swiss-Prot: February 6, 2007
Last sequence update: April 18, 2006
Last modified: April 3, 2013
This is version 38 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programPlant Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

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