PSAC_SYNP6
ID PSAC_SYNP6 Reviewed; 81 AA.
AC P31085;
DT 01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 3.
DT 03-AUG-2022, entry version 138.
DE RecName: Full=Photosystem I iron-sulfur center;
DE EC=1.97.1.12;
DE AltName: Full=9 kDa polypeptide;
DE AltName: Full=PSI-C;
DE AltName: Full=Photosystem I subunit VII;
DE AltName: Full=PsaC;
GN Name=psaC; OrderedLocusNames=syc0986_d;
OS Synechococcus sp. (strain ATCC 27144 / PCC 6301 / SAUG 1402/1) (Anacystis
OS nidulans).
OC Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus.
OX NCBI_TaxID=269084;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=8016272; DOI=10.1104/pp.104.4.1459;
RA Herman P.L., Adiwilaga K., Golbeck J.H., Weeks D.P.;
RT "Sequence of a psaC gene from the cyanobacterium Synechococcus sp. PCC
RT 6301.";
RL Plant Physiol. 104:1459-1461(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 27144 / PCC 6301 / SAUG 1402/1;
RX PubMed=17211581; DOI=10.1007/s11120-006-9122-4;
RA Sugita C., Ogata K., Shikata M., Jikuya H., Takano J., Furumichi M.,
RA Kanehisa M., Omata T., Sugiura M., Sugita M.;
RT "Complete nucleotide sequence of the freshwater unicellular cyanobacterium
RT Synechococcus elongatus PCC 6301 chromosome: gene content and
RT organization.";
RL Photosyn. Res. 93:55-67(2007).
RN [3]
RP PROTEIN SEQUENCE OF 2-19.
RX PubMed=1653017; DOI=10.1016/s0005-2728(05)80206-3;
RA Li N., Warren P.V., Golbeck J.H., Frank G., Zuber H., Bryant D.A.;
RT "Polypeptide composition of the Photosystem I complex and the Photosystem I
RT core protein from Synechococcus sp. PCC 6301.";
RL Biochim. Biophys. Acta 1059:215-225(1991).
RN [4]
RP MUTAGENESIS OF ASP-9; GLU-27 AND ASP-32.
RX PubMed=8794765; DOI=10.1021/bi9612834;
RA Rodday S.M., Do L.T., Chynwat V., Frank H.A., Biggins J.;
RT "Site-directed mutagenesis of the subunit PsaC establishes a surface-
RT exposed domain interacting with the photosystem I core binding site.";
RL Biochemistry 35:11832-11838(1996).
RN [5]
RP FUNCTION.
RX PubMed=9545061; DOI=10.1016/s0006-3495(98)77909-3;
RA Vassiliev I.R., Jung Y.-S., Yang F., Golbeck J.H.;
RT "PsaC subunit of photosystem I is oriented with iron-sulfur cluster F(B) as
RT the immediate electron donor to ferredoxin and flavodoxin.";
RL Biophys. J. 74:2029-2035(1998).
RN [6]
RP MUTAGENESIS OF THE C-TERMINUS.
RX PubMed=8621546; DOI=10.1074/jbc.271.15.8996;
RA Naver H., Scott M.P., Golbeck J.H., Moeller B.L., Scheller H.V.;
RT "Reconstitution of barley photosystem I with modified PSI-C allows
RT identification of domains interacting with PSI-D and PSI-A/B.";
RL J. Biol. Chem. 271:8996-9001(1996).
CC -!- FUNCTION: Apoprotein for the two 4Fe-4S centers FA and FB of
CC photosystem I (PSI); essential for photochemical activity. FB is the
CC terminal electron acceptor of PSI, donating electrons to ferredoxin.
CC The C-terminus interacts with PsaA/B/D and helps assemble the protein
CC into the PSI complex. Required for binding of PsaD and PsaE to PSI. PSI
CC is a plastocyanin/cytochrome c6-ferredoxin oxidoreductase, converting
CC photonic excitation into a charge separation, which transfers an
CC electron from the donor P700 chlorophyll pair to the spectroscopically
CC characterized acceptors A0, A1, FX, FA and FB in turn.
CC {ECO:0000269|PubMed:9545061}.
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 Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC Note=Binds 2 [4Fe-4S] clusters. Cluster 2 is most probably the
CC spectroscopically characterized electron acceptor FA and cluster 1 is
CC most probably FB.;
CC -!- SUBUNIT: The cyanobacterial PSI reaction center is composed of one copy
CC each of PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane; Peripheral membrane
CC protein; Cytoplasmic side.
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DR EMBL; U01536; AAA18220.1; -; Unassigned_DNA.
DR EMBL; AP008231; BAD79176.1; -; Genomic_DNA.
DR RefSeq; WP_011243298.1; NC_006576.1.
DR AlphaFoldDB; P31085; -.
DR SMR; P31085; -.
DR STRING; 269084.syc0986_d; -.
DR EnsemblBacteria; BAD79176; BAD79176; syc0986_d.
DR KEGG; syc:syc0986_d; -.
DR eggNOG; COG1143; Bacteria.
DR OMA; GHMSHAV; -.
DR Proteomes; UP000001175; Chromosome.
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:0009055; F:electron transfer activity; IEA:UniProtKB-UniRule.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0009773; P:photosynthetic electron transport in photosystem I; IEA:InterPro.
DR HAMAP; MF_01303; PSI_PsaC; 1.
DR InterPro; IPR017896; 4Fe4S_Fe-S-bd.
DR InterPro; IPR017900; 4Fe4S_Fe_S_CS.
DR InterPro; IPR017491; PSI_PsaC.
DR Pfam; PF12838; Fer4_7; 1.
DR TIGRFAMs; TIGR03048; PS_I_psaC; 1.
DR PROSITE; PS00198; 4FE4S_FER_1; 2.
DR PROSITE; PS51379; 4FE4S_FER_2; 2.
PE 1: Evidence at protein level;
KW 4Fe-4S; Direct protein sequencing; Electron transport; Iron; Iron-sulfur;
KW Membrane; Metal-binding; Oxidoreductase; Photosynthesis; Photosystem I;
KW Repeat; Thylakoid; Transport.
FT INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000269|PubMed:1653017"
FT CHAIN 2..81
FT /note="Photosystem I iron-sulfur center"
FT /id="PRO_0000062022"
FT DOMAIN 2..31
FT /note="4Fe-4S ferredoxin-type 1"
FT DOMAIN 39..68
FT /note="4Fe-4S ferredoxin-type 2"
FT BINDING 11
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 14
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 17
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 21
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 48
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 51
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 54
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 58
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT MUTAGEN 9
FT /note="D->A: Decreases assembly onto PSI cores (in vitro)."
FT /evidence="ECO:0000269|PubMed:8794765"
FT MUTAGEN 9
FT /note="D->R: Decreases assembly onto PSI cores in vitro, FA
FT and FB seems to assemble normally."
FT /evidence="ECO:0000269|PubMed:8794765"
FT MUTAGEN 27
FT /note="E->A: No effect."
FT /evidence="ECO:0000269|PubMed:8794765"
FT MUTAGEN 27
FT /note="E->R: Decreases assembly onto PSI cores in vitro, FA
FT and FB seem to assemble normally."
FT /evidence="ECO:0000269|PubMed:8794765"
FT MUTAGEN 32
FT /note="D->A: No effect."
FT /evidence="ECO:0000269|PubMed:8794765"
FT MUTAGEN 32
FT /note="D->R: Decreases assembly onto PSI cores in vitro, FA
FT and FB seems to assemble normally."
FT /evidence="ECO:0000269|PubMed:8794765"
FT MUTAGEN 72..81
FT /note="Missing: Required for stable assembly of the protein
FT onto PSI cores (in vitro)."
FT /evidence="ECO:0000269|PubMed:8621546"
SQ SEQUENCE 81 AA; 8798 MW; 40010FD9371A4AFB CRC64;
MSHSVKIYDT CIGCTQCVRA CPLDVLEMVP WDGCKAGQIA ASPRTEDCVG CKRCETACPT
DFLSIRVYLG AETTRSMGLA Y
