PSAB_BIGNA
ID PSAB_BIGNA Reviewed; 735 AA.
AC Q06J40;
DT 11-SEP-2007, integrated into UniProtKB/Swiss-Prot.
DT 31-OCT-2006, sequence version 1.
DT 03-AUG-2022, entry version 58.
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=PSI-B {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 Bigelowiella natans (Pedinomonas minutissima) (Chlorarachnion sp. (strain
OS CCMP621)).
OG Plastid; Chloroplast.
OC Eukaryota; Sar; Rhizaria; Cercozoa; Chlorarachniophyceae; Bigelowiella.
OX NCBI_TaxID=227086;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=16990439; DOI=10.1093/molbev/msl129;
RA Rogers M.B., Gilson P.R., Su V., McFadden G.I., Keeling P.J.;
RT "The complete chloroplast genome of the chlorarachniophyte Bigelowiella
RT natans: evidence for independent origins of chlorarachniophyte and euglenid
RT secondary endosymbionts.";
RL Mol. Biol. Evol. 24:54-62(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_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=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, chloroplast thylakoid membrane
CC {ECO:0000255|HAMAP-Rule:MF_00482}; Multi-pass membrane protein
CC {ECO:0000255|HAMAP-Rule:MF_00482}.
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; DQ851108; ABG91419.1; -; Genomic_DNA.
DR RefSeq; YP_778587.1; NC_008408.1.
DR AlphaFoldDB; Q06J40; -.
DR SMR; Q06J40; -.
DR GeneID; 4353004; -.
DR GO; GO:0009535; C:chloroplast 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 3: Inferred from homology;
KW 4Fe-4S; Chlorophyll; Chloroplast; Chromophore; Electron transport; Iron;
KW Iron-sulfur; Magnesium; Membrane; Metal-binding; Oxidoreductase;
KW Photosynthesis; Photosystem I; Plastid; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..735
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000300057"
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 176..200
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 274..292
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 329..352
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 368..394
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 416..438
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 521..539
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 579..600
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 647..669
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 708..728
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 563
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 572
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 658
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 666
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 674
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 675
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 735 AA; 82548 MW; C3F718A592867024 CRC64;
MKLRLFTSGI LGDDKRSMET TQDLWFFRIV HDFFATFEGV SVYQKIFASH FGQIALIFLW
ASGNLFYVSS QGNFEQWVSD PLHTRPIAHA IWDPQFGQSA VAAYTRAGAS GPVTLSTSGL
YQWWYTIGMR SNDDLSTASM FLLILSVLFL IAGFIHGYVP LFKPSLAFFK DAESRLNHHL
SALFGVSSLA WTGHLIHVAI PESRGQHIRW NNYLSTLPHP DGLAPFFSGN WSAYSTNPDT
FNHVFGTSNG AGSAILTFQG GLNPQTGSLW LTDIAHHHLA IAVLFIVAGH MYKTNWSIGH
NLQELVEGHN IINGRFNHKG LYQTVNTCLN LQLALALAAV GTICSLVAQH MYSLPAYAYM
AQDYVTQAAL YTHHQYIAGF IMCGAFAHGT IFLVTEYDPE INADNVLARF LENREVIISH
LSWVCLFLGF HTLGLYVHND VMLAFETPEK QILIEPIFAQ YIQAAQGKSS YDFNVLLSSS
VSDAYLIPTQ SANKGIWLSG WLNSINNNTN SLFIEIGPGD FLVHHAIALG LHTTTLILVK
GALDARGSKL MPDKKRFGYG FPCDGPGRGG TCDISAWDAF YLAIFWMLNT IGWVTFYWHW
KHLGIWQGNT KQFYESSTYL MGWLRDYLWL NSSQLINGYN PLGMNALSVW SWMFLFGHLI
YATGFMFLIS WRGYWQELIE TLVWAHDRLP IVLWPEKPVA LTIVQARFVG LIHFTVGYIL
TYAAFLIAST SGKFS
