PSAB_SYNSC
ID PSAB_SYNSC Reviewed; 737 AA.
AC Q3AMS4;
DT 11-SEP-2007, integrated into UniProtKB/Swiss-Prot.
DT 22-NOV-2005, sequence version 1.
DT 03-AUG-2022, entry version 99.
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};
GN OrderedLocusNames=Syncc9605_0332;
OS Synechococcus sp. (strain CC9605).
OC Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus;
OC unclassified Synechococcus.
OX NCBI_TaxID=110662;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CC9605;
RG US DOE Joint Genome Institute;
RA Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T.,
RA Hammon N., Israni S., Pitluck S., Schmutz J., Martinez M., Larimer F.,
RA Land M., Kyrpides N., Ivanova N., Richardson P.;
RT "Complete sequence of Synechococcus sp. CC9605.";
RL Submitted (JUL-2005) to the EMBL/GenBank/DDBJ databases.
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=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_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
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_00482}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC Rule:MF_00482}; 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; CP000110; ABB34108.1; -; Genomic_DNA.
DR RefSeq; WP_011363356.1; NC_007516.1.
DR AlphaFoldDB; Q3AMS4; -.
DR SMR; Q3AMS4; -.
DR STRING; 110662.Syncc9605_0332; -.
DR EnsemblBacteria; ABB34108; ABB34108; Syncc9605_0332.
DR KEGG; syd:Syncc9605_0332; -.
DR eggNOG; COG2885; Bacteria.
DR HOGENOM; CLU_016126_1_0_3; -.
DR OMA; FEQWVAD; -.
DR OrthoDB; 36958at2; -.
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_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; Chromophore; Electron transport; Iron; Iron-sulfur;
KW Magnesium; Membrane; Metal-binding; Oxidoreductase; Photosynthesis;
KW Photosystem I; Thylakoid; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..737
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000300024"
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 333..356
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 372..398
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 420..442
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; 81835 MW; 32B5C3391A54F038 CRC64;
MATKFPSFSQ GLAQDPTTRR IWYGIATAHD FESHDGMTEE RLYQKLFSTH FGHLAIIGLW
VSGNLFHIAW QGNFEQWVAD PLHVRPIAHA IWDPHFGQGA IDAFTQAGAS SPVNIAYSGL
YHWFYTIGMK TNAELYQGSI FMMILSAWAL FAGWLHLQPK FRPSLAWFKN AESRLNHHLA
VLFGFSSIAW TGHLVHVAIP EARGQHVGWD NFLNVLPHPA GLGPFFTGNW GVYAENPDSL
NQVFGSSEGA GTAILTFLGG FHPQTEALWL TDIAHHHLAI GCIFVIAGHM YRTNFGIGHS
IKEILETHNP PKGTPGDLGA GHKGLYDTIN NSLHFQLGLA LASLGVVTSL VAQHMYSMPS
YAFIAKDYTT QAALYTHHQY IAIALMCGAF AHGAIFFIRD YDPEANKDNV LARMLEHKEA
IISHLSWVSL FLGFHTLGLY VHNDVVVAFG TPEKQILVEP VFAQFVQAAS GKAMYGMDVL
LSNASSSASL AAQNIPGEHY WLDAINGNTD VFLPIGPGDF LVHHAIALGL HTTTLILVKG
ALDARGSKLM PDKKDFGYSF PCDGPGRGGT CDISAWDAFY LAVFWALNTV GWLTFYWHWK
HLAIWSGNVA QFNESSTYLM GWFRDYLWLN SSQLINGYNP FGSNNLAVWA WMFLFGHLVW
ATGFMFLISW RGYWQELIET IVWAHQRSPI ANMMGYRDKP VALSIVQARV VGLAHFTVGY
VLTYAAFLIA STSGKFG