ID   CYF_GRATL               Reviewed;         310 AA.
AC   Q6B8T0;
DT   21-JUN-2005, integrated into UniProtKB/Swiss-Prot.
DT   13-SEP-2004, sequence version 1.
DT   03-AUG-2022, entry version 74.
DE   RecName: Full=Cytochrome f {ECO:0000255|HAMAP-Rule:MF_00610};
DE   Flags: Precursor;
GN   Name=petA {ECO:0000255|HAMAP-Rule:MF_00610}; OrderedLocusNames=Grc000124;
OS   Gracilaria tenuistipitata var. liui (Red alga).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Florideophyceae; Rhodymeniophycidae; Gracilariales;
OC   Gracilariaceae; Agarophyton; Agarophyton tenuistipitatum.
OX   NCBI_TaxID=285951;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=15638458; DOI=10.1007/s00239-004-2638-3;
RA   Hagopian J.C., Reis M., Kitajima J.P., Bhattacharya D., de Oliveira M.C.;
RT   "Comparative analysis of the complete plastid genome sequence of the red
RT   alga Gracilaria tenuistipitata var. liui provides insights into the
RT   evolution of rhodoplasts and their relationship to other plastids.";
RL   J. Mol. Evol. 59:464-477(2004).
CC   -!- FUNCTION: Component of the cytochrome b6-f complex, which mediates
CC       electron transfer between photosystem II (PSII) and photosystem I
CC       (PSI), cyclic electron flow around PSI, and state transitions.
CC       {ECO:0000255|HAMAP-Rule:MF_00610}.
CC   -!- COFACTOR:
CC       Name=heme; Xref=ChEBI:CHEBI:30413;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_00610};
CC       Note=Binds 1 heme group covalently. {ECO:0000255|HAMAP-Rule:MF_00610};
CC   -!- SUBUNIT: The 4 large subunits of the cytochrome b6-f complex are
CC       cytochrome b6, subunit IV (17 kDa polypeptide, petD), cytochrome f and
CC       the Rieske protein, while the 4 small subunits are PetG, PetL, PetM and
CC       PetN. The complex functions as a dimer (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC       {ECO:0000255|HAMAP-Rule:MF_00610}; Single-pass membrane protein
CC       {ECO:0000255|HAMAP-Rule:MF_00610}.
CC   -!- SIMILARITY: Belongs to the cytochrome f family. {ECO:0000255|HAMAP-
CC       Rule:MF_00610}.
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DR   EMBL; AY673996; AAT79705.1; -; Genomic_DNA.
DR   RefSeq; YP_063630.1; NC_006137.1.
DR   AlphaFoldDB; Q6B8T0; -.
DR   SMR; Q6B8T0; -.
DR   GeneID; 2943940; -.
DR   GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0031361; C:integral component of thylakoid membrane; IEA:InterPro.
DR   GO; GO:0009055; F:electron transfer activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0020037; F:heme binding; IEA:InterPro.
DR   GO; GO:0005506; F:iron ion binding; IEA:InterPro.
DR   GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR   Gene3D; 2.60.40.830; -; 1.
DR   HAMAP; MF_00610; Cytb6_f_cytF; 1.
DR   InterPro; IPR024058; Cyt-f_TM.
DR   InterPro; IPR002325; Cyt_f.
DR   InterPro; IPR024094; Cyt_f_lg_dom.
DR   InterPro; IPR036826; Cyt_f_lg_dom_sf.
DR   InterPro; IPR011054; Rudment_hybrid_motif.
DR   Pfam; PF01333; Apocytochr_F_C; 1.
DR   Pfam; PF16639; Apocytochr_F_N; 1.
DR   PRINTS; PR00610; CYTOCHROMEF.
DR   SUPFAM; SSF103431; SSF103431; 1.
DR   SUPFAM; SSF49441; SSF49441; 1.
DR   SUPFAM; SSF51246; SSF51246; 1.
DR   PROSITE; PS51010; CYTF; 1.
PE   3: Inferred from homology;
KW   Chloroplast; Electron transport; Heme; Iron; Membrane; Metal-binding;
KW   Photosynthesis; Plastid; Signal; Thylakoid; Transmembrane;
KW   Transmembrane helix; Transport.
FT   SIGNAL          1..26
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00610"
FT   CHAIN           27..310
FT                   /note="Cytochrome f"
FT                   /id="PRO_0000023814"
FT   TRANSMEM        276..296
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00610"
FT   BINDING         27
FT                   /ligand="heme"
FT                   /ligand_id="ChEBI:CHEBI:30413"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00610"
FT   BINDING         47
FT                   /ligand="heme"
FT                   /ligand_id="ChEBI:CHEBI:30413"
FT                   /note="covalent"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00610"
FT   BINDING         50
FT                   /ligand="heme"
FT                   /ligand_id="ChEBI:CHEBI:30413"
FT                   /note="covalent"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00610"
FT   BINDING         51
FT                   /ligand="heme"
FT                   /ligand_id="ChEBI:CHEBI:30413"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00610"
SQ   SEQUENCE   310 AA;  34394 MW;  898828DD0299A561 CRC64;
     MNIKLTLLVL ISIINLMIIQ PIQTLAFPIY AQQGYENPRE ATGRIVCANC HLAQKPIKIE
     APKTVLPNSI FEAIVKIPYD TNNKQLLGNG IKGSINTGAV MILPEGFKLA PKNLLSEELR
     EKTKNVYIQP YSTTKDNILL VGPLAGEKNQ EIIFPILSPD PSKDKNIHFL KYPIYIGANR
     GRGQVYPTGD KSNNNPIVSL NTGKVTKIIS LEKGGYKIEI EKDNGEIYTE NIPQGLNLMV
     SQGSQVVANQ NLTDDPNVGG FGQTEIEIVL QSPSRIKGMI VFFFTVTIAQ IFFVLKKKQW
     EKVQAAEINF