ID   PSAA_PROM5              Reviewed;         760 AA.
AC   A2BYP9;
DT   10-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   20-FEB-2007, sequence version 1.
DT   27-MAR-2024, entry version 95.
DE   RecName: Full=Photosystem I P700 chlorophyll a apoprotein A1 {ECO:0000255|HAMAP-Rule:MF_00458};
DE            EC=1.97.1.12 {ECO:0000255|HAMAP-Rule:MF_00458};
DE   AltName: Full=PsaA {ECO:0000255|HAMAP-Rule:MF_00458};
GN   Name=psaA {ECO:0000255|HAMAP-Rule:MF_00458};
GN   OrderedLocusNames=P9515_17031;
OS   Prochlorococcus marinus (strain MIT 9515).
OC   Bacteria; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC   Prochlorococcaceae; Prochlorococcus.
OX   NCBI_TaxID=167542;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=MIT 9515;
RX   PubMed=18159947; DOI=10.1371/journal.pgen.0030231;
RA   Kettler G.C., Martiny A.C., Huang K., Zucker J., Coleman M.L., Rodrigue S.,
RA   Chen F., Lapidus A., Ferriera S., Johnson J., Steglich C., Church G.M.,
RA   Richardson P., Chisholm S.W.;
RT   "Patterns and implications of gene gain and loss in the evolution of
RT   Prochlorococcus.";
RL   PLoS Genet. 3:2515-2528(2007).
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_00458}.
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_00458};
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_00458};
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_00458}.
CC   -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC       Rule:MF_00458}; Multi-pass membrane protein {ECO:0000255|HAMAP-
CC       Rule:MF_00458}.
CC   -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP-
CC       Rule:MF_00458}.
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DR   EMBL; CP000552; ABM72910.1; -; Genomic_DNA.
DR   RefSeq; WP_011821002.1; NC_008817.1.
DR   AlphaFoldDB; A2BYP9; -.
DR   SMR; A2BYP9; -.
DR   STRING; 167542.P9515_17031; -.
DR   GeneID; 60200996; -.
DR   KEGG; pmc:P9515_17031; -.
DR   eggNOG; COG2885; Bacteria.
DR   HOGENOM; CLU_016126_1_0_3; -.
DR   OrthoDB; 499313at2; -.
DR   Proteomes; UP000001589; Chromosome.
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; Photosystem I PsaA/PsaB; 1.
DR   HAMAP; MF_00458; PSI_PsaA; 1.
DR   InterPro; IPR006243; PSI_PsaA.
DR   InterPro; IPR001280; PSI_PsaA/B.
DR   InterPro; IPR020586; PSI_PsaA/B_CS.
DR   InterPro; IPR036408; PSI_PsaA/B_sf.
DR   NCBIfam; TIGR01335; psaA; 1.
DR   PANTHER; PTHR30128; OUTER MEMBRANE PROTEIN, OMPA-RELATED; 1.
DR   PANTHER; PTHR30128:SF77; PHOTOSYSTEM I P700 CHLOROPHYLL A APOPROTEIN A1; 1.
DR   Pfam; PF00223; PsaA_PsaB; 1.
DR   PIRSF; PIRSF002905; PSI_A; 1.
DR   PRINTS; PR00257; PHOTSYSPSAAB.
DR   SUPFAM; SSF81558; Photosystem I subunits PsaA/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..760
FT                   /note="Photosystem I P700 chlorophyll a apoprotein A1"
FT                   /id="PRO_0000294203"
FT   TRANSMEM        76..99
FT                   /note="Helical; Name=I"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        162..185
FT                   /note="Helical; Name=II"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        201..225
FT                   /note="Helical; Name=III"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        309..327
FT                   /note="Helical; Name=IV"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        368..391
FT                   /note="Helical; Name=V"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        407..433
FT                   /note="Helical; Name=VI"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        455..477
FT                   /note="Helical; Name=VII"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        551..569
FT                   /note="Helical; Name=VIII"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        609..630
FT                   /note="Helical; Name=IX"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        674..696
FT                   /note="Helical; Name=X"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        734..754
FT                   /note="Helical; Name=XI"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   REGION          1..22
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        7..22
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   BINDING         593
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_00458"
FT   BINDING         602
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_00458"
FT   BINDING         685
FT                   /ligand="divinylchlorophyll a'"
FT                   /ligand_id="ChEBI:CHEBI:189420"
FT                   /ligand_label="A1"
FT                   /ligand_part="Mg"
FT                   /ligand_part_id="ChEBI:CHEBI:25107"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   BINDING         693
FT                   /ligand="divinyl chlorophyll a"
FT                   /ligand_id="ChEBI:CHEBI:73095"
FT                   /ligand_label="A3"
FT                   /ligand_part="Mg"
FT                   /ligand_part_id="ChEBI:CHEBI:25107"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   BINDING         701
FT                   /ligand="divinyl chlorophyll a"
FT                   /ligand_id="ChEBI:CHEBI:73095"
FT                   /ligand_label="A3"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   BINDING         702
FT                   /ligand="phylloquinone"
FT                   /ligand_id="ChEBI:CHEBI:18067"
FT                   /ligand_label="A"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
SQ   SEQUENCE   760 AA;  83716 MW;  E73A0882B41063EC CRC64;
     MTISPPESGE KDKKILESPV KADPRPIDFA KLDKPGFWSS KLSKGPKTTT WIWNLHADAH
     DFDVHTGDAE EATRKIFSAH FGHLAVIFIW MSAAFFHGAR FSNYSGWLAD PTHVKPGAQQ
     VWAIVGQEML NGDLGANYNG IQISSGVFHM WRAWGITNES ELMALAIGAV VMAALMLHAG
     IFHYHKAAPK MEWFQDVESM MNHHLAGLLG LGSLAWAGHT IHIGAPTAAL LDAIDAGSPL
     IINGKEIATI ADIPMPHQLC DPQIVGQIFP GLASGTGNFF SLNWFAFSDF LTFKGGLNPV
     TGSLWMTDIA HHHLAIAVLF IIAGHMYRTN YGIGHSMKEI LDAHQGDPIL FPAPRGHQGL
     FDFMAESRHA QLSVNLALLG SLSIIISHHM YAMPPYPYIA TDYMTVLGLF THHMWIGGLF
     IVGAGAHAGI AMVRDYDPAK HIDNVLDRVL KARDALISHL NWVCMWLGFH SFGLYIHNDT
     MRALGRPQDM FSDKAIQLQP IFAQWIQNIQ SSGVGTTLLE GNGVSQVFNG ETISVGGKVA
     MTGIPLGTAD LMIHHIHAFQ IHVTVLILLK GVLYARSSRL IPDKASLGFR FPCDGPGRGG
     TCQVSSWDHV FLALFWMYNC LSIVIFHFSW KMQSDVWGLT GGNFAQSAIT INGWLRDFLW
     AQAAQVLTSY GQSISMYGLM FLGAHFIWAF SLMFLFSGRG YWQELFESIV WAHNKLKVAP
     TIQPRALSIT QGRAVGVTHF LVGGIATTWA FFHARLFGIG
//