PSAB_PROMP
ID PSAB_PROMP Reviewed; 742 AA.
AC Q9RC07;
DT 16-NOV-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-2000, sequence version 1.
DT 03-AUG-2022, entry version 136.
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=PsaB {ECO:0000255|HAMAP-Rule:MF_00482};
GN Name=psaB {ECO:0000255|HAMAP-Rule:MF_00482}; OrderedLocusNames=PMM1523;
OS Prochlorococcus marinus subsp. pastoris (strain CCMP1986 / NIES-2087 /
OS MED4).
OC Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC Prochlorococcus.
OX NCBI_TaxID=59919;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=16228480; DOI=10.1023/a:1006445810996;
RA van der Staay G.W.M., Moon-van der Staay S.Y., Garczarek L., Partensky F.;
RT "Rapid evolutionary divergence of photosystem I core subunits PsaA and PsaB
RT in the marine prokaryote Prochlorococcus.";
RL Photosyn. Res. 65:131-139(2000).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCMP1986 / NIES-2087 / MED4;
RX PubMed=12917642; DOI=10.1038/nature01947;
RA Rocap G., Larimer F.W., Lamerdin J.E., Malfatti S., Chain P., Ahlgren N.A.,
RA Arellano A., Coleman M., Hauser L., Hess W.R., Johnson Z.I., Land M.L.,
RA Lindell D., Post A.F., Regala W., Shah M., Shaw S.L., Steglich C.,
RA Sullivan M.B., Ting C.S., Tolonen A., Webb E.A., Zinser E.R.,
RA Chisholm S.W.;
RT "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche
RT differentiation.";
RL Nature 424:1042-1047(2003).
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=PSI electron transfer chain: 5 divinyl chlorophyll a, 1 divinyl
CC chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core
CC antenna: 90 divinyl chlorophyll a, 22 carotenoids, 3 phospholipids and
CC 1 galactolipid. P700 is a divinyl chlorophyll a/divinyl chlorophyll a'
CC dimer, A0 is one or more divinyl chlorophyll a, A1 is one or both
CC phylloquinones and FX is a shared 4Fe-4S iron-sulfur center.
CC {ECO:0000255|HAMAP-Rule:MF_00482};
CC -!- SUBUNIT: The PsaA/B heterodimer binds the P700 divinyl chlorophyll
CC special pair and subsequent electron acceptors. PSI consists of a core
CC antenna complex that captures photons, and an electron transfer chain
CC that converts photonic excitation into a charge separation. The
CC cyanobacterial PSI reaction center is composed of one copy each of
CC PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes.
CC {ECO:0000255|HAMAP-Rule:MF_00482}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC Rule:MF_00482}; Multi-pass membrane protein {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
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DR EMBL; AJ133191; CAB64201.1; -; Genomic_DNA.
DR EMBL; BX548174; CAE19982.1; -; Genomic_DNA.
DR RefSeq; WP_011133151.1; NC_005072.1.
DR AlphaFoldDB; Q9RC07; -.
DR SMR; Q9RC07; -.
DR STRING; 59919.PMM1523; -.
DR EnsemblBacteria; CAE19982; CAE19982; PMM1523.
DR KEGG; pmm:PMM1523; -.
DR eggNOG; COG2885; Bacteria.
DR HOGENOM; CLU_016126_1_0_3; -.
DR OMA; FEQWVAD; -.
DR OrthoDB; 36958at2; -.
DR Proteomes; UP000001026; Chromosome.
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:0031676; C:plasma membrane-derived thylakoid membrane; IEA:UniProtKB-SubCell.
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; Chromophore; Electron transport; Iron; Iron-sulfur;
KW Magnesium; Membrane; Metal-binding; Oxidoreductase; Photosynthesis;
KW Photosystem I; Thylakoid; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..742
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000088649"
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 336..359
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 375..401
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 423..445
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 525..543
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 583..604
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 651..673
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 715..735
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 567
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 576
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 662
FT /ligand="divinyl chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:73095"
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 670
FT /ligand="divinyl chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:73095"
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 678
FT /ligand="divinyl chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:73095"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 679
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 742 AA; 82743 MW; 00DF1EDBE77050F9 CRC64;
MATKFPSFNQ GLAQDPTTRR IWYGIATAHD FESHDGMTEE KLYQKLFSTH FGHLAIIALW
VAGNLFHIAW QGNFEQFVLD PTHVRPIAHA IWDPHFGSGI TEAMTQAGAS GPVNIAYSGL
YHWWYTIGMR TNEQLFQASI FMSILACWTL FAGWLHLQPK FRPSLAWFKN NESRLNHHLA
VLFGFSSIAW TGHLVHVAIP ESRGIHVGWD NWLTVLPHPA GLAPFFTLNW GAYAQNPDTL
EQVFGTSEGA GTAIFTFLGG LHPQSEALWL TDIAHHHIAI GTVFIIAGHM YRNTFGIGHS
LKEITEAHNT RHPLDPHKGS FGINHDGIYE TVTNSLHFQL GLALAALGVA TSLVAQHMGA
LPSYAFIARD YTTQSALYTH HQYIAMFLMV GAFAHGAIFF VRDYDPELNK DNVLARVLGT
KEALISHLSW VTMILGFHTL GIYVHNDVVV AFGNPEKQIL IEPVFAQFVQ AAQGKMMYGF
NALLSDPTSS ASLAANSLPG NHYWMDLINR QDALSAFLPI GPADFLVHHA IALGLHTTAL
ILIKGALDAR GTKLIPDKKD LGYAFPCDGP GRGGTCDSSS WDAMYLAMFW ALNLIAWVTF
YWHWKHLAIW QGNVAQFNES GTYLMGWFRD YLWLNSAQLI NGYNPFGVNS LSVWAWMFLF
GHLVWATGFM FLISWRGYWQ ELIETLVWAH QRTPIANLVG WRDKPVALSI VQARLVGLAH
FTIGNILTFG AFVIASTSGK FG
