ID   ISIA_SYNP2              Reviewed;         342 AA.
AC   P31157; B1XL34;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1993, sequence version 1.
DT   03-AUG-2022, entry version 120.
DE   RecName: Full=Iron stress-induced chlorophyll-binding protein;
DE   AltName: Full=CP43';
GN   Name=isiA; OrderedLocusNames=SYNPCC7002_A1292;
OS   Synechococcus sp. (strain ATCC 27264 / PCC 7002 / PR-6) (Agmenellum
OS   quadruplicatum).
OC   Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus;
OC   unclassified Synechococcus.
OX   NCBI_TaxID=32049;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND INDUCTION.
RX   PubMed=1527503; DOI=10.1099/00221287-138-8-1613;
RA   Leonhardt K.G., Straus N.A.;
RT   "An iron stress operon involved in photosynthetic electron transport in the
RT   marine cyanobacterium Synechococcus sp. PCC 7002.";
RL   J. Gen. Microbiol. 138:1613-1621(1992).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27264 / PCC 7002 / PR-6;
RA   Li T., Zhao J., Zhao C., Liu Z., Zhao F., Marquardt J., Nomura C.T.,
RA   Persson S., Detter J.C., Richardson P.M., Lanz C., Schuster S.C., Wang J.,
RA   Li S., Huang X., Cai T., Yu Z., Luo J., Zhao J., Bryant D.A.;
RT   "Complete sequence of Synechococcus sp. PCC 7002.";
RL   Submitted (FEB-2008) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Functions as an antenna for photosystem I (PSI) under iron-
CC       limiting conditions, when phycobilisomes disappear. In the
CC       (PSI)3(Isi3)18 complex most of the harvested energy is probably used by
CC       PSI; in other PSI-containing supercomplexes a large part of the energy
CC       will probably not be used for light harvesting, but rather is
CC       dissipated to protect the organism from light damage.
CC       {ECO:0000250|UniProtKB:P15347}.
CC   -!- COFACTOR:
CC       Name=chlorophyll a; Xref=ChEBI:CHEBI:58416;
CC         Evidence={ECO:0000250|UniProtKB:P15347};
CC       Note=Chlorophyll a. {ECO:0000250|UniProtKB:P15347};
CC   -!- COFACTOR:
CC       Name=all-trans-beta-carotene; Xref=ChEBI:CHEBI:17579;
CC         Evidence={ECO:0000250|UniProtKB:P15347};
CC   -!- SUBUNIT: Under iron-starvation forms a complex with PSI trimers, where
CC       the trimer is surrounded by a ring composed of 18 IsiA subunits.
CC       {ECO:0000250|UniProtKB:P15347}.
CC   -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane
CC       {ECO:0000250|UniProtKB:P15347}; Multi-pass membrane protein
CC       {ECO:0000305}.
CC   -!- INDUCTION: By iron stress. {ECO:0000269|PubMed:1527503}.
CC   -!- SIMILARITY: Belongs to the PsbB/PsbC family. IsiA/Pcb subfamily.
CC       {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=ACA99289.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};
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DR   EMBL; M88253; AAA27317.1; -; Genomic_DNA.
DR   EMBL; CP000951; ACA99289.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; WP_041443458.1; NC_010475.1.
DR   AlphaFoldDB; P31157; -.
DR   SMR; P31157; -.
DR   STRING; 32049.SYNPCC7002_A1292; -.
DR   EnsemblBacteria; ACA99289; ACA99289; SYNPCC7002_A1292.
DR   KEGG; syp:SYNPCC7002_A1292; -.
DR   eggNOG; ENOG502Z92X; Bacteria.
DR   HOGENOM; CLU_028310_0_0_3; -.
DR   OMA; FGYNWED; -.
DR   Proteomes; UP000001688; 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:0016168; F:chlorophyll binding; IEA:UniProtKB-KW.
DR   GO; GO:0009767; P:photosynthetic electron transport chain; IEA:InterPro.
DR   InterPro; IPR000932; PS_antenna-like.
DR   InterPro; IPR036001; PS_II_antenna-like_sf.
DR   PANTHER; PTHR33180; PTHR33180; 1.
DR   Pfam; PF00421; PSII; 2.
DR   SUPFAM; SSF161077; SSF161077; 1.
PE   2: Evidence at transcript level;
KW   Chlorophyll; Chromophore; Membrane; Photosynthesis; Photosystem I;
KW   Reference proteome; Stress response; Thylakoid; Transmembrane;
KW   Transmembrane helix.
FT   CHAIN           1..342
FT                   /note="Iron stress-induced chlorophyll-binding protein"
FT                   /id="PRO_0000077559"
FT   TRANSMEM        27..47
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        63..83
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        88..108
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        202..222
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        239..259
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        302..322
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   342 AA;  37594 MW;  7FF89FB1A8AD7288 CRC64;
     MQTYDNPDVK YEWWAGNARF ADLSGQFIGA HVAHAALIVF WAGAFTLFEI SYFDPTLPMG
     EQNLILLPHL ATLGLGIEGN GAINTEPYFV IGAIHLISSA VLAAGGLFHV LRGPQDLKTA
     TGPARRFHFD WEDPKQLGLI LGHHLLLLGL GAFLLVAKAM YFGGLYDTAT QTVRLVTEPT
     LDPAVIYGYQ THFATVDNLE DIVGGHIYVG VLLVAGGIWH ILVPPLQWAK KVLLFSGEAI
     LSYSLGAIAL AGFVAAYFCA VNTTAYPVEF YGPVLDVKLS IVPYFADTIE LPMNEHTSRA
     WLANAHFFFA FFFLQGHLWH ALRAMGFDFR RVEKVLSDPL DA