PSAB2_NOSS1
ID PSAB2_NOSS1 Reviewed; 742 AA.
AC Q8YLI4;
DT 03-APR-2002, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 3.
DT 03-AUG-2022, entry version 121.
DE RecName: Full=Photosystem I P700 chlorophyll a apoprotein A2 2;
DE EC=1.97.1.12;
DE AltName: Full=PsaB 2;
GN Name=psaB2; OrderedLocusNames=alr5314;
OS Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576).
OC Bacteria; Cyanobacteria; Nostocales; Nostocaceae; Nostoc.
OX NCBI_TaxID=103690;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=PCC 7120 / SAG 25.82 / UTEX 2576;
RX PubMed=11759840; DOI=10.1093/dnares/8.5.205;
RA Kaneko T., Nakamura Y., Wolk C.P., Kuritz T., Sasamoto S., Watanabe A.,
RA Iriguchi M., Ishikawa A., Kawashima K., Kimura T., Kishida Y., Kohara M.,
RA Matsumoto M., Matsuno A., Muraki A., Nakazaki N., Shimpo S., Sugimoto M.,
RA Takazawa M., Yamada M., Yasuda M., Tabata S.;
RT "Complete genomic sequence of the filamentous nitrogen-fixing
RT cyanobacterium Anabaena sp. strain PCC 7120.";
RL DNA Res. 8:205-213(2001).
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 (By similarity).
CC {ECO:0000250}.
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;
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:0000250};
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 (By
CC similarity). {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000250}; Multi-
CC pass membrane protein {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000305}.
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DR EMBL; BA000019; BAB77013.1; -; Genomic_DNA.
DR PIR; AB2470; AB2470.
DR RefSeq; WP_010999438.1; NZ_RSCN01000005.1.
DR AlphaFoldDB; Q8YLI4; -.
DR SMR; Q8YLI4; -.
DR STRING; 103690.17134453; -.
DR EnsemblBacteria; BAB77013; BAB77013; BAB77013.
DR KEGG; ana:alr5314; -.
DR eggNOG; COG2885; Bacteria.
DR OMA; FGHVAII; -.
DR OrthoDB; 36958at2; -.
DR Proteomes; UP000002483; 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 INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000250"
FT CHAIN 2..742
FT /note="Photosystem I P700 chlorophyll a apoprotein A2 2"
FT /id="PRO_0000088642"
FT TRANSMEM 46..69
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255"
FT TRANSMEM 135..158
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255"
FT TRANSMEM 175..199
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255"
FT TRANSMEM 273..291
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255"
FT TRANSMEM 334..357
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255"
FT TRANSMEM 373..399
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255"
FT TRANSMEM 421..443
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255"
FT TRANSMEM 524..542
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255"
FT TRANSMEM 583..604
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255"
FT TRANSMEM 651..673
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255"
FT TRANSMEM 715..735
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255"
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:0000250"
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:0000250"
FT BINDING 662
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:0000250"
FT BINDING 670
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:0000250"
FT BINDING 678
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000250"
FT BINDING 679
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000250"
SQ SEQUENCE 742 AA; 83860 MW; 81771CAA7431E07A CRC64;
MATKYPKFSR DLAQDPTTRR IWYAIATGND FESHDGMTEE NLYQKIFATH FGHVAIIFLW
ASSLLFHVAW QGNFEQWIKD PLHIRPIAHA IWDPHFGKPA IEAFSQGGAN YPVNIAYSGV
YHWWYTIGMR TNNDLYQGSV FLLLLAALFL FAGWLHLQPK FRPSLTWFKS AEPRLNHHLA
GLFGVSSLAW AGHLIHVAIP ESRGVHVGWR NFLTTLPHPA GLTPFWTGNW GVYAQNADTT
GHIFGTSQGA GTAILTFLGG FHPQTESLWL TDMAHHHLAI AVIFIIAGHM YRTNFGIGHS
IKEMLNAKQF FGIRTEGQFN LPHQGLYDTY NNSLHFQLSI HLAALGTALS LVAQHMYSLP
PYAFIAKDYT TQAALYTHHQ YIAGFLMIGA FAHAGIFWIR DYDPEQNQGN VLDRVLKHKE
AIISHLSWVS LFLGFHTLGI YVHNDVVVAF GTPEKQILIE PVFAQFIQAA HGKLLYGMDT
LLSNPDSIAY TAWPNHANVW LPNWLDAINS GTNSLFLTIG PGDFLVHHAI ALGLHTTTLI
CVKGALDARG TKLMPDKKDF GFTFPCDGPG RGGTCQTSSW EQSFYLALFW MLNLLGWVTF
YWHWKHLGVW QGNVAQFNEN STYLMGWFRD YLWANSAQLI NGYNPYGTNN LSVWAWMFLF
GHLVWATGFM FLISWRGYWQ ELIETLVWAH ERTPLANLVR WKDKPVALSI VQGWLVGLAH
FTVGYILTYA AFLIASTAGK FG
