PSAB_CYAPA
ID PSAB_CYAPA Reviewed; 737 AA.
AC P48113;
DT 01-FEB-1996, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1996, sequence version 1.
DT 03-AUG-2022, entry version 100.
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};
OS Cyanophora paradoxa.
OG Plastid; Cyanelle.
OC Eukaryota; Glaucocystophyceae; Cyanophoraceae; Cyanophora.
OX NCBI_TaxID=2762;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=UTEX LB 555 / Pringsheim;
RA Stirewalt V.L., Michalowski C.B., Loeffelhardt W., Bohnert H.J.,
RA Bryant D.A.;
RT "Nucleotide sequence of the cyanelle DNA from Cyanophora paradoxa.";
RL Plant Mol. Biol. Rep. 13:327-332(1995).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=UTEX LB 555 / Pringsheim;
RA Loeffelhardt W., Stirewalt V.L., Michalowski C.B., Annarella M.,
RA Farley J.Y., Schluchter W.M., Chung S., Newmann-Spallart C., Steiner J.M.,
RA Jakowitsch J., Bohnert H.J., Bryant D.A.;
RT "The complete sequence of the cyanelle genome of Cyanophora paradoxa: the
RT genetic complexity of a primitive plastid.";
RL (In) Schenk H.E.A., Herrmann R., Jeon K.W., Mueller N.E., Schwemmler W.
RL (eds.);
RL Eukaryotism and symbiosis, pp.40-48, Springer-Verlag, Heidelberg (1997).
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 cytochrome c6-ferredoxin oxidoreductase, converting photonic
CC excitation into a charge separation, which transfers an electron from
CC the donor P700 chlorophyll pair to the spectroscopically characterized
CC acceptors A0, A1, FX, FA and FB in turn. Oxidized P700 is reduced on
CC the lumenal side of the thylakoid membrane by cytochrome c6 (By
CC similarity). {ECO:0000250}.
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, cyanelle thylakoid membrane
CC {ECO:0000250}; 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; U30821; AAA81182.1; -; Genomic_DNA.
DR PIR; T06839; T06839.
DR RefSeq; NP_043151.1; NC_001675.1.
DR PDB; 7DR0; EM; 3.30 A; B=1-737.
DR PDB; 7DR1; EM; 3.20 A; B=1-737.
DR PDB; 7DR2; EM; 3.80 A; aB/bB/cB/dB=1-737.
DR PDBsum; 7DR0; -.
DR PDBsum; 7DR1; -.
DR PDBsum; 7DR2; -.
DR AlphaFoldDB; P48113; -.
DR SMR; P48113; -.
DR GeneID; 801522; -.
DR GO; GO:0033115; C:cyanelle 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 1: Evidence at protein level;
KW 3D-structure; 4Fe-4S; Chlorophyll; Chromophore; Cyanelle;
KW Electron transport; Iron; Iron-sulfur; Magnesium; Membrane; Metal-binding;
KW Oxidoreductase; Photosynthesis; Photosystem I; Plastid; Thylakoid;
KW Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..737
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000088613"
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 520..538
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 578..599
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 646..668
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 710..730
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 562
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 571
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 657
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 665
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 673
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 674
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 737 AA; 82237 MW; 8D30B982B6BA951E CRC64;
MGTKFPKASQ ALAQDPTTRR IWYGIATAND FETNDGITEE NLYQKIFASH FGHLAIIFLW
TSGNLFHVAW QGNFEQWVKD PLNTRPIAHA ISDPHFGQRA IEAFSQAGAS SPVNISYSGV
YQWWYTQGMR TNEELYNGAI FLLILSALSL FAGWLHLQPK FRPNLSWFKN AESRLNHHLG
GLFGTSSLAW TGHIVHVAIP ESRGQHVGWD NFLQVAPHPA GLQPFFTGNW GVYTENPDTA
NHVFGSSDGA GTAILTFLGG FHPQTQSLWL TDIAHHHLAI AVLFIVAGHM YRTNFGIGHS
IKEILNGHRP PGGRLGAGHV GLYDTVNNSL HFQLGLALAA LGVITSLVAQ HMYSIPPYAY
LARDFTTQAA LYTHHQYIAG FLMVGAFAHG AIFLVRDYDA EQNKNNVLAR IIDHKEAIIS
HLSWVSLFLG FHTLGLYVHN DVVQAFGTPE KQILIEPVFA QWIQSVHGKS LYGFEVLLNN
ADSITRVAPG SAQPIWLPGW LDAINSGNNS LFLTIGPGDF LVHHAIALGL HTTTLILVKG
ALDARGSKLM PDKKDFGYSF PCDGPGRGGT CDISAWDAFY LAVFWMLNTI GWTTFYWHWK
HLGVWQGNVA QFNESSTYLM GWFRDYLWLN SSQLINGYNP FGMNNLSVWA WMFLFGHLIW
ATGFMFLISW RGYWQELIET LVWAHERTPL ANLVRWKDKP VALSIVQARL VGLAHFAVGY
IVTYAAFLIA STASKFG
