PSAB_EUGGR
ID PSAB_EUGGR Reviewed; 734 AA.
AC P19431;
DT 01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1991, sequence version 1.
DT 03-AUG-2022, entry version 114.
DE RecName: Full=Photosystem I P700 chlorophyll a apoprotein A2 {ECO:0000255|HAMAP-Rule:MF_00482};
DE EC=1.97.1.12 {ECO:0000255|HAMAP-Rule:MF_00482};
DE AltName: Full=PSI-B {ECO:0000255|HAMAP-Rule:MF_00482};
DE AltName: Full=PsaB {ECO:0000255|HAMAP-Rule:MF_00482};
GN Name=psaB {ECO:0000255|HAMAP-Rule:MF_00482};
OS Euglena gracilis.
OG Plastid; Chloroplast.
OC Eukaryota; Discoba; Euglenozoa; Euglenida; Spirocuta; Euglenophyceae;
OC Euglenales; Euglenaceae; Euglena.
OX NCBI_TaxID=3039;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=Z / UTEX 753;
RX PubMed=2836086; DOI=10.1007/bf00365651;
RA Cushman J.C., Hallick R.B., Price C.A.;
RT "The two genes for the P700 chlorophyll a apoproteins on the Euglena
RT gracilis chloroplast genome contain multiple introns.";
RL Curr. Genet. 13:159-171(1988).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=Z / UTEX 753;
RX PubMed=8346031; DOI=10.1093/nar/21.15.3537;
RA Hallick R.B., Hong L., Drager R.G., Favreau M.R., Monfort A., Orsat B.,
RA Spielmann A., Stutz E.;
RT "Complete sequence of Euglena gracilis chloroplast DNA.";
RL Nucleic Acids Res. 21:3537-3544(1993).
CC -!- FUNCTION: PsaA and PsaB bind P700, the primary electron donor of
CC photosystem I (PSI), as well as the electron acceptors A0, A1 and FX.
CC PSI is a plastocyanin/cytochrome c6-ferredoxin oxidoreductase,
CC converting photonic excitation into a charge separation, which
CC transfers an electron from the donor P700 chlorophyll pair to the
CC spectroscopically characterized acceptors A0, A1, FX, FA and FB in
CC turn. Oxidized P700 is reduced on the lumenal side of the thylakoid
CC membrane by plastocyanin or cytochrome c6. {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin]
CC = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin];
CC Xref=Rhea:RHEA:30407, Rhea:RHEA-COMP:10000, Rhea:RHEA-COMP:10001,
CC Rhea:RHEA-COMP:10039, Rhea:RHEA-COMP:10040, ChEBI:CHEBI:29036,
CC ChEBI:CHEBI:30212, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738,
CC ChEBI:CHEBI:49552; EC=1.97.1.12; Evidence={ECO:0000255|HAMAP-
CC Rule:MF_00482};
CC -!- COFACTOR:
CC Note=P700 is a chlorophyll a/chlorophyll a' dimer, A0 is one or more
CC chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe-
CC 4S iron-sulfur center. {ECO:0000255|HAMAP-Rule:MF_00482};
CC -!- SUBUNIT: The PsaA/B heterodimer binds the P700 chlorophyll special pair
CC and subsequent electron acceptors. PSI consists of a core antenna
CC complex that captures photons, and an electron transfer chain that
CC converts photonic excitation into a charge separation. The eukaryotic
CC PSI reaction center is composed of at least 11 subunits.
CC {ECO:0000255|HAMAP-Rule:MF_00482}.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC {ECO:0000255|HAMAP-Rule:MF_00482}; Multi-pass membrane protein
CC {ECO:0000255|HAMAP-Rule:MF_00482}.
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
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DR EMBL; Z11874; CAA77911.1; -; Genomic_DNA.
DR EMBL; M37526; AAA84452.1; -; Genomic_DNA.
DR EMBL; X70810; CAA50094.1; -; Genomic_DNA.
DR PIR; S26072; S26072.
DR RefSeq; NP_041907.1; NC_001603.2.
DR AlphaFoldDB; P19431; -.
DR SMR; P19431; -.
DR GeneID; 807516; -.
DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0009522; C:photosystem I; IEA:UniProtKB-KW.
DR GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR GO; GO:0016168; F:chlorophyll binding; IEA:UniProtKB-KW.
DR GO; GO:0009055; F:electron transfer activity; IEA:UniProtKB-UniRule.
DR GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR Gene3D; 1.20.1130.10; -; 1.
DR HAMAP; MF_00482; PSI_PsaB; 1.
DR InterPro; IPR001280; PSI_PsaA/B.
DR InterPro; IPR020586; PSI_PsaA/B_CS.
DR InterPro; IPR036408; PSI_PsaA/B_sf.
DR InterPro; IPR006244; PSI_PsaB.
DR Pfam; PF00223; PsaA_PsaB; 1.
DR PIRSF; PIRSF002905; PSI_A; 1.
DR PRINTS; PR00257; PHOTSYSPSAAB.
DR SUPFAM; SSF81558; SSF81558; 1.
DR TIGRFAMs; TIGR01336; psaB; 1.
DR PROSITE; PS00419; PHOTOSYSTEM_I_PSAAB; 1.
PE 3: Inferred from homology;
KW 4Fe-4S; Chlorophyll; Chloroplast; Chromophore; Electron transport; Iron;
KW Iron-sulfur; Magnesium; Membrane; Metal-binding; Oxidoreductase;
KW Photosynthesis; Photosystem I; Plastid; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..734
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000088614"
FT TRANSMEM 46..69
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 135..158
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 175..199
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 273..291
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 330..353
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 369..395
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 417..439
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 517..535
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 575..596
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 643..665
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 707..727
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 559
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 568
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 654
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B1"
FT /ligand_part="Mg"
FT /ligand_part_id="ChEBI:CHEBI:25107"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 662
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /ligand_part="Mg"
FT /ligand_part_id="ChEBI:CHEBI:25107"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 670
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 671
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT CONFLICT 603..604
FT /note="QG -> R (in Ref. 1; AAA84452)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 734 AA; 82696 MW; 3DF6330171C12696 CRC64;
MATKFPKFSQ GLAQDPTTRR IWFGIATSHD FESHDGMTEN NLYQKIFASH FGQLAIIFLW
TSGNLFHVAW QGNFEQWIKD PLHIRPIAHA ISDPHFGQPA IEAFTRSQFP GPVNIAYSGV
YQWWYTIGLR TNVDLYNGSM FLLFIATLAL FAGWLHLEPK YSPKVSWFKD AESRLNHHLS
ALFGLSSLAW SGHLIHVAIP ESRGIHVRWD NFLSQLPHPS GLEPFFKGNW SLYSENPDSL
THVFGTASGA GTAVLTFLGG FHPETKSLWL TDIAHHHLAI AVLFIVAGHM YRTNFAIGHR
IDDILNAHKA PSGKLGLGHF GLYETINNSL HFQLGLALAS LGVITSLVAQ HMYSLSPYAF
LIQDRTTMAA LYTHHQYIAG FIMTGAFAHG AIFFIRDFDE EKNKGNVLSR ILDHKEAIIS
HLSWVTLFLG FHTLGLYVHN DVMQAFGTPE KQILIEPVFA QWIQSAHGKN IYELNILLSS
DSSNAFSASQ AIWLPGWLNG INDKSTSLFL QIGPGDFLVH HAIALGLHTT TLILVKGALD
ARGSRLMPDK KDFGYSFPCD GPGRGGTCDI SAWDAFYLAV FWMLNTIGWT TFYWHWKHIT
LWQGNVGQFN ESSTYLMGWL RDYLWLNSSQ LINGYNPFGM NSLAVWGWMF LFGHLVWATG
FMFLISWRGY WQELIETLVW AHERTPITNV FKWTDKPVAL SIVQARLVGL AHFSVGYVFT
YAAFLIASTS AKFG
