PSAB_SYNJB
ID PSAB_SYNJB Reviewed; 744 AA.
AC Q2JQ90;
DT 11-SEP-2007, integrated into UniProtKB/Swiss-Prot.
DT 07-MAR-2006, sequence version 1.
DT 03-AUG-2022, entry version 96.
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=CYB_0021;
OS Synechococcus sp. (strain JA-2-3B'a(2-13)) (Cyanobacteria bacterium
OS Yellowstone B-Prime).
OC Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus;
OC unclassified Synechococcus.
OX NCBI_TaxID=321332;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=JA-2-3B'a(2-13);
RX PubMed=18059494; DOI=10.1038/ismej.2007.46;
RA Bhaya D., Grossman A.R., Steunou A.-S., Khuri N., Cohan F.M., Hamamura N.,
RA Melendrez M.C., Bateson M.M., Ward D.M., Heidelberg J.F.;
RT "Population level functional diversity in a microbial community revealed by
RT comparative genomic and metagenomic analyses.";
RL ISME J. 1:703-713(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 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; CP000240; ABD01022.1; -; Genomic_DNA.
DR RefSeq; WP_011431693.1; NC_007776.1.
DR AlphaFoldDB; Q2JQ90; -.
DR SMR; Q2JQ90; -.
DR STRING; 321332.CYB_0021; -.
DR KEGG; cyb:CYB_0021; -.
DR eggNOG; COG2885; Bacteria.
DR HOGENOM; CLU_016126_1_0_3; -.
DR OMA; FEQWVAD; -.
DR OrthoDB; 36958at2; -.
DR Proteomes; UP000001938; 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..744
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000300026"
FT TRANSMEM 48..71
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 137..160
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 177..201
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 275..293
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 337..360
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 376..402
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 424..446
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 527..545
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 585..606
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 653..675
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 717..737
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 569
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 578
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 664
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 672
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 680
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 681
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 744 AA; 82729 MW; 94EEC154AD1BC715 CRC64;
MTTATRFPQF SQDLASDPTT RRLWYGIATA HDFETHDGMT EERLYQKLFA THFGHLAIIF
LWASGNVFHI AWQGNYEQWV ANPTGVTPIA HAIWDPHFGK AAVEAFTQPG GGGPVNAAYS
GLYYWFNTIG LRTNGDLYAG AIGLLLLAAV FLFAGWLHLQ PRFRPSLSWF KNAEARLNHH
LAGLFGVSSL AWTGHLVHVA IPESRGQHVG WDNFLTTLPH PAGLKPFFTL NWGVYAQNPD
TANHVWGTAE GAGTAILTFL GGFNPNTQSL WLTDMAHHHL AIAVIFIVAG HMYRTNWGIG
HSIREILGAH NPPKGTPFGG LLGEGHKGLY DTVNNSLHFQ LALALACLGV VTSLVAQHMY
ALNPYVFMSM DHTTEAALYT HHQYIAGFLM VGAFAHGAIF LVRDYDPEAN KNNVLARVLD
HKEAIISHLS WVSLFLGFHT LGLYVHNDVM QAFGTPEKQI LIEPVFAQFI QASHGKMIYG
MDVLLSNPDS LASTAWPNYG NVWLPGWLQA INDPNGSLFL PIGPGDFLVH HAIALGLHTT
TLILVKGALD ARGSKLMPDK KDFGYSFPCD GPGRGGTCDI SAWDAFYLAM FWMLNTIGWV
TFYWHWKQLG VWSGNTAQFN ENSTYLMGWL RDYLWANSAQ LINGYNPYGM NNLAVWAWMF
LFGHLVWATG FMFLISWRGY WQELIETLVW AHERTPLAKL IRWKDKPVAM SIVQGRLVGL
AHFTVGYVLT YAAFVIASTA SQSG
