PSAB_THEVL
ID PSAB_THEVL Reviewed; 741 AA.
AC P0A409; P25897;
DT 15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 2.
DT 03-AUG-2022, entry version 73.
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 Thermostichus vulcanus (Synechococcus vulcanus).
OC Bacteria; Cyanobacteria; Thermostichales; Thermostichaceae; Thermostichus.
OX NCBI_TaxID=32053;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=1558952; DOI=10.1007/bf00020021;
RA Shimizu T., Hiyama T., Ikeuchi M., Inoue Y.;
RT "Nucleotide sequences of the psaA and psaB genes encoding the photosystem I
RT core proteins from the thermophilic cyanobacterium Synechococcus
RT vulcanus.";
RL Plant Mol. Biol. 18:785-791(1992).
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; D10986; BAA01760.1; -; Genomic_DNA.
DR PDB; 6K33; EM; 2.74 A; aB/bB/cB=2-741.
DR PDBsum; 6K33; -.
DR AlphaFoldDB; P0A409; -.
DR SMR; P0A409; -.
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 1: Evidence at protein level;
KW 3D-structure; 4Fe-4S; Chlorophyll; Chromophore; Electron transport; Iron;
KW Iron-sulfur; Magnesium; Membrane; Metal-binding; Oxidoreductase;
KW Photosynthesis; Photosystem I; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000250"
FT CHAIN 2..741
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000088654"
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 334..357
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 373..399
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 421..443
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 524..542
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 582..603
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 650..672
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 714..734
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 566
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 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_00482"
FT BINDING 661
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 669
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 677
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 678
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 741 AA; 83044 MW; 74961EF21401FB40 CRC64;
MATKFPKFSQ DLAQDPTTRR IWYAIAMAHD FESHDGMTEE NLYQKIFASH FGHLAIIFLW
VSGSLFHVAW QGNFEQWVQD PVNTRPIAHA IWDPQFGKAA VDAFTQAGAS NPVDIAYSGV
YHWWYTIGMR TNGDLYQGAI FLLILASLAL FAGWLHLQPK FRPSLSWFKN AESRLNHHLA
GLFGVSSLAW AGHLIHVAIP ESRGQHVGWD NFLSTMPHPA GLAPFFTGNW GVYAQNPDTA
SHVFGTAQGA GTAILTFLGG FHPQTESLWL TDMAHHHLAI AVLFIVAGHM YRTQFGIGHS
IKEMMDAKDF FGTKVEGPFN MPHQGIYETY NNSLHFQLGW HLACLGVITS LVAQHMYSLP
PYAFIAQDHT TMAALYTHHQ YIAGFLMVGA FAHGAIFLVR DYDPAQNKGN VLDRVLQHKE
AIISHLSWVS LFLGFHTLGL YVHNDVVVAF GTPEKQILIE PVFAQFIQAA HGKLLYGFDT
LLSNPDSIAS TAWPNYGNVW LPGWLDAINS GTNSLFLTIG PGDFLVHHAI ALGLHTTTLI
LVKGALDARG SKLMPDKKDF GYAFPCDGPG RGGTCDISAW DAFYLAMFWM LNTIGWVTFY
WHWKHLGVWE GNVAQFNESS TYLMGWLRDY LWLNSSQLIN GYNPFGTNNL SVWAWMFLFG
HLVWATGFMF LISWRGYWQE LIETLVWAHE RTPLANLVRW KDKPVALSIV QARLVGLAHF
SVGYILTYAA FLIASTAAKF G
