ID   PSAA_PROM1              Reviewed;         768 AA.
AC   A2C4V3;
DT   10-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   20-FEB-2007, sequence version 1.
DT   27-MAR-2024, entry version 96.
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=NATL1_19571;
OS   Prochlorococcus marinus (strain NATL1A).
OC   Bacteria; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC   Prochlorococcaceae; Prochlorococcus.
OX   NCBI_TaxID=167555;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=NATL1A;
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; CP000553; ABM76513.1; -; Genomic_DNA.
DR   RefSeq; WP_011824482.1; NC_008819.1.
DR   AlphaFoldDB; A2C4V3; -.
DR   SMR; A2C4V3; -.
DR   KEGG; pme:NATL1_19571; -.
DR   eggNOG; COG2885; Bacteria.
DR   HOGENOM; CLU_016126_1_0_3; -.
DR   Proteomes; UP000002592; 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..768
FT                   /note="Photosystem I P700 chlorophyll a apoprotein A1"
FT                   /id="PRO_0000294204"
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        310..328
FT                   /note="Helical; Name=IV"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        369..392
FT                   /note="Helical; Name=V"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        408..434
FT                   /note="Helical; Name=VI"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        456..478
FT                   /note="Helical; Name=VII"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        559..577
FT                   /note="Helical; Name=VIII"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        617..638
FT                   /note="Helical; Name=IX"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        682..704
FT                   /note="Helical; Name=X"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   TRANSMEM        742..762
FT                   /note="Helical; Name=XI"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT   BINDING         601
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         610
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         693
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         701
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         709
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         710
FT                   /ligand="phylloquinone"
FT                   /ligand_id="ChEBI:CHEBI:18067"
FT                   /ligand_label="A"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
SQ   SEQUENCE   768 AA;  84390 MW;  5F51B544D4E4471E CRC64;
     MTISPPEKEQ KKEPVLDKPI ETDAIPVDFS KLDKPGFWSK SLAKGPKTTT WIWNLHADAH
     DFDTHVGDLQ ETSRKVFSAH FGHLAVIFIW MSAAFFHGAR FSNYSGWLSD PTHVKPGAQV
     VWPIVGQEML NADLGGNYHG IQITSGIFQM WRGWGITNET ELMALAIGAL LMAAIMLHGG
     IYHYHKAAPK LDWFRNLESM LNHHIAGLVG LGSIAWAGHC IHIGAPTAAL MDAIDAGKPL
     IIDGIPIASI ADMPLPHELC NPAIASQIFP GLAGRTVENF FTTNWWAFSD FLTFKGGLNP
     VTGSLWMTDI SHHHLAFGVL AVLGGHLYRT MFGIGHSLKE ILDNHAGDPI LFPAPNGHKG
     IYEFLANSWH AQLGLNLAMI GSLSIIISHH MYAMPPYPYL SIDYPTVLGL FTHHMWIGGL
     FIVGAAAHAG IAMIRDYDPA VHIDNVLDRI LKARDALISH LNWACMFLGF HSFGLYIHND
     VMRALGRPAD MFSDTGIQLQ PVFAQWIQNI HNSAAGSTTL AGANVNLQPG LVSEVFNGSV
     SQVGGKIGIA PIPLGTADFM IHHIHAFTIH VTLLILLKGV LFARSSRLIP DKANLGFRFP
     CDGPGRGGTC QVSSWDHVFL GLFWMYNGLS VVIFHFSWKM QSDVWGLTGG NFAQSSITIN
     GWLRDFLWAQ SSQVLTSYGQ PISMYGLMFL GAHFVWAFSL MFLFSGRGYW QELFESIIWA
     HNKLNLAPTI QPRALSITQG RAVGAAHFLL GGIATTWAFF HARLIGLG
//