PSAB_PROMT
ID PSAB_PROMT Reviewed; 742 AA.
AC Q46IV5;
DT 11-SEP-2007, integrated into UniProtKB/Swiss-Prot.
DT 13-SEP-2005, sequence version 1.
DT 03-AUG-2022, entry version 98.
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}; OrderedLocusNames=PMN2A_1083;
OS Prochlorococcus marinus (strain NATL2A).
OC Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC Prochlorococcus.
OX NCBI_TaxID=59920;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=NATL2A;
RX PubMed=18159947; DOI=10.1371/journal.pgen.0030231;
RA Kettler G.C., Martiny A.C., Huang K., Zucker J., Coleman M.L., Rodrigue S.,
RA Chen F., Lapidus A., Ferriera S., Johnson J., Steglich C., Church G.M.,
RA Richardson P., Chisholm S.W.;
RT "Patterns and implications of gene gain and loss in the evolution of
RT Prochlorococcus.";
RL PLoS Genet. 3:2515-2528(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=PSI electron transfer chain: 5 divinyl chlorophyll a, 1 divinyl
CC chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core
CC antenna: 90 divinyl chlorophyll a, 22 carotenoids, 3 phospholipids and
CC 1 galactolipid. P700 is a divinyl chlorophyll a/divinyl chlorophyll a'
CC dimer, A0 is one or more divinyl chlorophyll a, A1 is one or both
CC phylloquinones and FX is a shared 4Fe-4S iron-sulfur center.
CC {ECO:0000255|HAMAP-Rule:MF_00482};
CC -!- SUBUNIT: The PsaA/B heterodimer binds the P700 divinyl chlorophyll
CC special pair and subsequent electron acceptors. PSI consists of a core
CC antenna complex that captures photons, and an electron transfer chain
CC that 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; CP000095; AAZ58573.1; -; Genomic_DNA.
DR RefSeq; WP_011295427.1; NC_007335.2.
DR AlphaFoldDB; Q46IV5; -.
DR SMR; Q46IV5; -.
DR STRING; 59920.PMN2A_1083; -.
DR EnsemblBacteria; AAZ58573; AAZ58573; PMN2A_1083.
DR KEGG; pmn:PMN2A_1083; -.
DR HOGENOM; CLU_016126_1_0_3; -.
DR OMA; FEQWVAD; -.
DR OrthoDB; 36958at2; -.
DR PhylomeDB; Q46IV5; -.
DR Proteomes; UP000002535; Chromosome.
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; Reference proteome; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..742
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000300022"
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 336..359
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 375..401
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 423..445
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 525..543
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 583..604
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 651..673
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 715..735
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 567
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 576
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 662
FT /ligand="divinyl chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:73095"
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 670
FT /ligand="divinyl chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:73095"
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 678
FT /ligand="divinyl chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:73095"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 679
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 742 AA; 82846 MW; EDEDEFBE1CD80364 CRC64;
MATKFPSFSQ GLAQDPTTRR IWYGIATAHD FESHDGMTEE QLYQKLFSTH FGHLAIIGLW
VAGNLFHIAW QGNFEQWVLD PLHTRPIAHA IWDPHFGQGL TDALTQAGAT SPVNIAYSGL
YHWWYTIGMR TNEQLFQGAI FINILVCWLL FAGWLHLQPK YRPSLAWFKN AESQLNHHLA
VLFGFSSIAW TGHLIHVAIP ESRGIHVGWE NWLTVMPHPE GLTPFFSGNW GAYAQNPDSI
DAVFGTSQGA GTAIFTFLGG LHPQSESLWL TDIAHHHLAI GVVFIIAGHM YRTNFGIGHS
LKEIIEAHNT SHPKDPHRGY FGIKHNGLFE TVNNSLHFQL GLALASLGVA CSLVAQHMGA
LPSYAFIARD YTTQSALYTH HQYIAMFLMV GAFSHGAIFF VRDYDPELNK DNVLARILST
KEALISHLSW VTMLLGFHTL GIYVHNDVVV AFGTPEKQIL IEPVFAQFAQ AASGKMMYGF
NALLANASSS ASIAANSMPG NHYWMDMINR PDALTNFLPI GPADFLVHHA IALGLHTTAL
ILIKGALDAR GTKLIPDKKD LGFAFPCDGP GRGGTCDSSS WDATYLAMFW ALNTIAWITF
YWHWKHLAIW MGNTAQFNES GTYLMGWFRD YLWLNSSQLI NGYNPFGVNA LSPWAWMFLF
GHLIWATGFM FLISWRGYWQ ELIETLVWAH QRTPIANLVG WRDKPVALSI VQARLVGLTH
FTVGNFVTFG AFVIASTSGK FG
