PSAA_MASLA
ID PSAA_MASLA Reviewed; 752 AA.
AC O52474;
DT 15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-1998, sequence version 1.
DT 03-AUG-2022, entry version 103.
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};
OS Mastigocladus laminosus (Fischerella sp.).
OC Bacteria; Cyanobacteria; Nostocales; Hapalosiphonaceae; Mastigocladus.
OX NCBI_TaxID=83541;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=PCC 7605;
RA Sun J., He Z.-Y., Nechushtai R., Chitnis P.R.;
RT "Molecular cloning of the psaA and psaB genes for the core proteins of
RT photosystem I from the thermophilic cyanobacterium Mastigocladus
RT laminosus.";
RL (er) Plant Gene Register PGR98-041(1998).
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 chlorophyll a, 1 chlorophyll a', 2
CC phylloquinones and 3 4Fe-4S clusters. PSI core antenna: 90 chlorophyll
CC a, 22 carotenoids, 3 phospholipids and 1 galactolipid. P700 is a
CC chlorophyll a/chlorophyll a' dimer, A0 is one or more chlorophyll a, A1
CC is one or both phylloquinones and FX is a shared 4Fe-4S iron-sulfur
CC center. {ECO:0000255|HAMAP-Rule:MF_00458};
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
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; AF038558; AAC12866.1; -; Genomic_DNA.
DR AlphaFoldDB; O52474; -.
DR SMR; O52474; -.
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_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 PANTHER; PTHR30128:SF61; PTHR30128:SF61; 1.
DR Pfam; PF00223; PsaA_PsaB; 1.
DR PIRSF; PIRSF002905; PSI_A; 1.
DR PRINTS; PR00257; PHOTSYSPSAAB.
DR SUPFAM; SSF81558; SSF81558; 1.
DR TIGRFAMs; TIGR01335; psaA; 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..752
FT /note="Photosystem I P700 chlorophyll a apoprotein A1"
FT /id="PRO_0000088586"
FT TRANSMEM 73..96
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 159..182
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 198..222
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 294..312
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 349..372
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 388..414
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 436..458
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 533..551
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 591..612
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 666..688
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT TRANSMEM 726..746
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT BINDING 575
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 584
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 677
FT /ligand="chlorophyll a'"
FT /ligand_id="ChEBI:CHEBI:189419"
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 685
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
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 693
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="A3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
FT BINDING 694
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="A"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00458"
SQ SEQUENCE 752 AA; 83374 MW; 717D3C5A7D728AE2 CRC64;
MTISPPEREE KKARVIVDND PVPTSFELWA KPGHFDRTLA RGPKTTTWIW NLHALAHDFD
THTSDLEDIS RKIFAAHFGH LAVVTLWLSG MIFHGARFSN YEAWLSDPLH VKPSAQVVWP
IVGQDILNGD VGGGFHGIQI TSGLFQIWRG WGITNSFQLY VTAIGGLVLA GLFLFAGWFH
YHKRAPKLEW FQNVESMLNH HLAVLLGCGS LGWAGHLIHV SAPTNKLLDA GVSVKDIPLP
HEFILNKGLL TELYPGFASG ITPFFTLNWG QYADFLTFKG GLNPVTGGLW LTDISHHHLA
IAVLFIIAGH MYRTNWGIGH SIKEILENHK GPFTGEGHKG LYENMTTSWH AQLATNLAFL
GSLTIIVAHH MYAMPPYPYL ATDYATQLCI FTHHMWIGGF LIVGGAAHAT IFMVRDYDPV
VNQNNVLDRV IRHRDAIISH LNWVCIFLGF HSFGLYVHND TMRALGRPQD MFSDTAIQLQ
PVFAQWVQNI HTLAPGSTAP NALEPASYAF GGGIVAVGGK VAMMPIALGT ADFLVHHIHA
FTIHVTVLIL LKGFLFARNS RLIPDKANLG FRFPCDGPGR GGTCQVSGWD HVFLGLFWMY
NSISIVIFHF SWKMQSDVWG TVDAAGNVTH ITGGNWAQSA LTINGWLRDF LWAQSVQVIN
SYGSALSAYG LMFLGAHFIW AFSLMFLFSG RGYWQELIES IVWAHNKLKV APAIQPRALS
IIQGRAVGVA HYLLGGIATT WAFFHAHILS LG
