ID PSAB_GOSBA Reviewed; 734 AA. AC A0ZZ34; DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot. DT 23-JAN-2007, sequence version 1. DT 13-SEP-2023, entry version 60. 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 Gossypium barbadense (Sea-island cotton) (Egyptian cotton). OG Plastid; Chloroplast. OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae; OC rosids; malvids; Malvales; Malvaceae; Malvoideae; Gossypium. OX NCBI_TaxID=3634; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RX PubMed=17159292; DOI=10.1266/ggs.81.311; RA Ibrahim R.I.H., Azuma J., Sakamoto M.; RT "Complete nucleotide sequence of the cotton (Gossypium barbadense L.) RT chloroplast genome with a comparative analysis of sequences among 9 dicot RT plants."; RL Genes Genet. Syst. 81:311-321(2006). 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 -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP- CC Rule:MF_00482}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; AP009123; BAF41246.1; -; Genomic_DNA. DR RefSeq; YP_913186.1; NC_008641.1. DR AlphaFoldDB; A0ZZ34; -. DR SMR; A0ZZ34; -. DR GeneID; 4575212; -. DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell. 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; Photosystem I PsaA/PsaB; 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 NCBIfam; TIGR01336; psaB; 1. DR PANTHER; PTHR30128; OUTER MEMBRANE PROTEIN, OMPA-RELATED; 1. DR PANTHER; PTHR30128:SF75; PHOTOSYSTEM I P700 CHLOROPHYLL A APOPROTEIN A2; 1. DR Pfam; PF00223; PsaA_PsaB; 1. DR PIRSF; PIRSF002905; PSI_A; 1. DR PRINTS; PR00257; PHOTSYSPSAAB. DR SUPFAM; SSF81558; Photosystem I subunits PsaA/PsaB; 1. DR PROSITE; PS00419; PHOTOSYSTEM_I_PSAAB; 1. PE 3: Inferred from homology; KW 4Fe-4S; Chlorophyll; Chloroplast; Chromophore; Electron transport; Iron; KW Iron-sulfur; Magnesium; Membrane; Metal-binding; Oxidoreductase; KW Photosynthesis; Photosystem I; Plastid; Thylakoid; Transmembrane; KW Transmembrane helix; Transport. FT CHAIN 1..734 FT /note="Photosystem I P700 chlorophyll a apoprotein A2" FT /id="PRO_0000277115" 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; 82388 MW; 82BEC221B89E9812 CRC64; MALRFPRFSQ GLAQDPTTRR IWFGIATAHD FESHDDITEE RLYQNIFASH FGQLAIIFLW TSGNLFHVAW QGNFEAWVQD PLHVRPIAHA IWDPHFGQPA VEAFTRGGAP GPVNIAYSGV YQWWYTIGLR TNEDLYTGAL FLLFLSALSL IAGWLHLQPK WKPSVSWFKN AESRLNHHLS GLFGVSSLAW TGHLVHVAIP GSRGEYVRWN NFLDVLPHPQ GLGPFFSGQW NLYAQNPDSS SHLFGTSQGS GTAILTLLGG FHPQTQSLWL TDIAHHHLAI AILFLIAGHM YRTNFGIGHS IKDLLEAHIP PGGRLGRGHK GLYDTINNSI HFQLGLALAS LGVITSLVAQ HMYSLPAYAF IAQDFTTQAA LYTHHQYIAG FIMTGAFAHG AIFFIRDYNP EQNEDNVLAR MLDHKEAIIS HLSWASLFLG FHTLGLYVHN DVMLAFGTPE KQILIEPIFA QWIQSAHGKT SYGFDVLLSS TNGPAFNAGR SIWLPGWLNA VNENSNSLFL TIGPGDFLVH HAIALGLHTT TLILVKGALD ARGSKLMPDK KDFGYSFPCD GPGRGGTCDI SAWDAFYLAV FWMLNTIGWV TFYWHWKHIT LWQGNVSQFN ESSTYLMGWL RDYLWLNSSQ LINGYNPFGM NSLSVWAWMF LFGHLVWATG FMFLISWRGY WQELIETLAW AHERTPLANL IRWRDKPVAL SIVQARLVGL AHFSVGYIFT FAAFLIASTS GKFG //