PSAB_ANTAG
ID PSAB_ANTAG Reviewed; 734 AA.
AC Q85AV8;
DT 25-JUL-2003, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2003, sequence version 1.
DT 03-AUG-2022, entry version 86.
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 Anthoceros angustus (Hornwort) (Anthoceros formosae).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Anthocerotophyta;
OC Anthocerotopsida; Anthocerotidae; Anthocerotales; Anthocerotaceae;
OC Anthoceros.
OX NCBI_TaxID=48387;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA], AND RNA EDITING.
RX PubMed=12527781; DOI=10.1093/nar/gkg155;
RA Kugita M., Kaneko A., Yamamoto Y., Takeya Y., Matsumoto T., Yoshinaga K.;
RT "The complete nucleotide sequence of the hornwort (Anthoceros formosae)
RT chloroplast genome: insight into the earliest land plants.";
RL Nucleic Acids Res. 31:716-721(2003).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA], AND RNA EDITING.
RC TISSUE=Thallus;
RX PubMed=12711687; DOI=10.1093/nar/gkg327;
RA Kugita M., Yamamoto Y., Fujikawa T., Matsumoto T., Yoshinaga K.;
RT "RNA editing in hornwort chloroplasts makes more than half the genes
RT functional.";
RL Nucleic Acids Res. 31:2417-2423(2003).
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-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 plastocyanin.
CC {ECO:0000255|HAMAP-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; Multi-
CC pass membrane protein.
CC -!- RNA EDITING: Modified_positions=44 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 65 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 106 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 122 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 126 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 175 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 187 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 255 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 277 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 410 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 431 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 452 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 501 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 581 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 586 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 714 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 719 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}, 733 {ECO:0000269|PubMed:12527781,
CC ECO:0000269|PubMed:12711687}; Note=The nonsense codons at positions 44,
CC 106, 122, 410 and 452 are modified to sense codons.;
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
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DR EMBL; AB086179; BAC55348.1; -; Genomic_DNA.
DR EMBL; AB087440; BAC55441.1; -; mRNA.
DR RefSeq; NP_777412.1; NC_004543.1.
DR AlphaFoldDB; Q85AV8; -.
DR SMR; Q85AV8; -.
DR GeneID; 2553391; -.
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 2: Evidence at transcript level;
KW 4Fe-4S; Chlorophyll; Chloroplast; Chromophore; Electron transport; Iron;
KW Iron-sulfur; Magnesium; Membrane; Metal-binding; Oxidoreductase;
KW Photosynthesis; Photosystem I; Plastid; RNA editing; Thylakoid;
KW Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..734
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000088602"
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 517..535
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 575..596
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 643..665
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 707..727
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 559
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 568
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 654
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 662
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 670
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 671
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 734 AA; 82550 MW; AB970D036CE79E6C CRC64;
MASRFPKFSQ GLSQDPTTRR IWFGIATAHD FESHDNITEE RLYQKIFASH FGQLAIIFLW
TSGNLFHVAW QGNFEAWVQD PLHVRPIAHA IWDPHFGEPA VEAFTRGGAL GPVNIAYSGV
YQWWYTIGLR TIQDLYIGAL FLLFLAAVFL IAGWLHLQPK WKPSVSWFKN AESRLNHHLS
GLFGVSSLAW AGHLIHVAIP ESRGEHVRWD NLLTALPHPQ GLKPFFEGQW GIYAENADSS
SHLFSTSQGA GTAILTFIGG FHPQTQSLWL TDIAHHHLAI AVVFIIAGHM YRTNFGIGHS
IKEILETHTP PGGRLGRGHK GLYDTINNSL HFQLGLALAS TGVITSLVAQ HMYSLPSYAY
IAQDFTTQAA LYTHHQYIAG FIMTGAFAHG AIFFIRDYNP EQNKDNVLAR MLEHKEAIIS
HLSWASLFLG FHTLGLYVHN DVMLAFGTPE KQILIEPVFA QWIQSAHGKT LYGFDLLLSS
ADSPAFNAGQ SIWLPGWLDA INNNSNSLFL TIGPGDFLVH HAIALGLHTT TLILVKGALD
ARGSKLMPDK KEFGYSFPCD GPGRGGTCDI SAWDAFYLAV FWMLNTIGWV TFYWHWKHIT
LWQGNVAQFN ESSTYLMGWL RDYLWLNSSQ LINGYNPFGM NSLSVWAWMF LFGHLVWATG
FMFLISWRGY WQELIETLTW AHERTPLANL VRWRDKPVAL SIVQARLVGL THFSVGYIFT
YAAFLIASTS GKFG
