ID A0A2T1CLT2_9CYAN Unreviewed; 222 AA.
AC A0A2T1CLT2;
DT 18-JUL-2018, integrated into UniProtKB/TrEMBL.
DT 18-JUL-2018, sequence version 1.
DT 27-MAR-2024, entry version 20.
DE RecName: Full=Cytochrome b6 {ECO:0000256|ARBA:ARBA00035697, ECO:0000256|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000256|HAMAP-Rule:MF_00633};
GN ORFNames=C7B62_14130 {ECO:0000313|EMBL:PSB09203.1};
OS Pleurocapsa sp. CCALA 161.
OC Bacteria; Cyanobacteriota; Cyanophyceae; Pleurocapsales; Hyellaceae;
OC Pleurocapsa.
OX NCBI_TaxID=2107688 {ECO:0000313|EMBL:PSB09203.1, ECO:0000313|Proteomes:UP000239836};
RN [1] {ECO:0000313|EMBL:PSB09203.1, ECO:0000313|Proteomes:UP000239836}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCALA 161 {ECO:0000313|EMBL:PSB09203.1,
RC ECO:0000313|Proteomes:UP000239836};
RA Cohen D.B., Kent A.D.;
RL Submitted (FEB-2018) to the EMBL/GenBank/DDBJ databases.
RN [2] {ECO:0000313|EMBL:PSB09203.1, ECO:0000313|Proteomes:UP000239836}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCALA 161 {ECO:0000313|EMBL:PSB09203.1,
RC ECO:0000313|Proteomes:UP000239836};
RA Moore K.R., Magnabosco C., Momper L., Gold D.A., Bosak T., Fournier G.P.;
RT "The ancient ancestry and fast evolution of plastids.";
RL Submitted (MAR-2018) to the EMBL/GenBank/DDBJ databases.
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:0000256|ARBA:ARBA00003068, ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- COFACTOR:
CC Name=heme b; Xref=ChEBI:CHEBI:60344;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_00633};
CC Note=Binds 2 heme b groups non-covalently with two histidine residues
CC as axial ligands. {ECO:0000256|HAMAP-Rule:MF_00633};
CC -!- COFACTOR:
CC Name=heme c; Xref=ChEBI:CHEBI:61717;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_00633};
CC Note=Binds one heme group covalently by a single cysteine link with no
CC axial amino acid ligand. This heme was named heme ci.
CC {ECO:0000256|HAMAP-Rule:MF_00633};
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. {ECO:0000256|ARBA:ARBA00025834,
CC ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000256|HAMAP-
CC Rule:MF_00633}; Multi-pass membrane protein {ECO:0000256|HAMAP-
CC Rule:MF_00633}. Membrane {ECO:0000256|ARBA:ARBA00004141}; Multi-pass
CC membrane protein {ECO:0000256|ARBA:ARBA00004141}.
CC -!- MISCELLANEOUS: Heme 1 (or BH or b566) is high-potential and absorbs at
CC about 566 nm, and heme 2 (or BL or b562) is low-potential and absorbs
CC at about 562 nm. {ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily.
CC {ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- CAUTION: The sequence shown here is derived from an EMBL/GenBank/DDBJ
CC whole genome shotgun (WGS) entry which is preliminary data.
CC {ECO:0000313|EMBL:PSB09203.1}.
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DR EMBL; PVWF01000054; PSB09203.1; -; Genomic_DNA.
DR AlphaFoldDB; A0A2T1CLT2; -.
DR InParanoid; A0A2T1CLT2; -.
DR OrthoDB; 9804503at2; -.
DR Proteomes; UP000239836; Unassembled WGS sequence.
DR GO; GO:0031676; C:plasma membrane-derived thylakoid membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0045158; F:electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity; IEA:UniProtKB-UniRule.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR CDD; cd00284; Cytochrome_b_N; 1.
DR HAMAP; MF_00633; Cytb6_f_cytb6; 1.
DR InterPro; IPR005797; Cyt_b/b6_N.
DR InterPro; IPR023530; Cyt_B6_PetB.
DR InterPro; IPR027387; Cytb/b6-like_sf.
DR InterPro; IPR048259; Cytochrome_b_N_euk/bac.
DR InterPro; IPR016174; Di-haem_cyt_TM.
DR PANTHER; PTHR19271; CYTOCHROME B; 1.
DR PANTHER; PTHR19271:SF16; CYTOCHROME B; 1.
DR Pfam; PF00033; Cytochrome_B; 1.
DR PIRSF; PIRSF000032; Cytochrome_b6; 1.
DR SUPFAM; SSF81342; Transmembrane di-heme cytochromes; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 3: Inferred from homology;
KW Electron transport {ECO:0000256|HAMAP-Rule:MF_00633};
KW Heme {ECO:0000256|HAMAP-Rule:MF_00633};
KW Iron {ECO:0000256|HAMAP-Rule:MF_00633};
KW Membrane {ECO:0000256|HAMAP-Rule:MF_00633, ECO:0000256|SAM:Phobius};
KW Metal-binding {ECO:0000256|HAMAP-Rule:MF_00633};
KW Photosynthesis {ECO:0000256|ARBA:ARBA00022531, ECO:0000256|HAMAP-
KW Rule:MF_00633}; Reference proteome {ECO:0000313|Proteomes:UP000239836};
KW Transmembrane {ECO:0000256|HAMAP-Rule:MF_00633, ECO:0000256|SAM:Phobius};
KW Transmembrane helix {ECO:0000256|HAMAP-Rule:MF_00633,
KW ECO:0000256|SAM:Phobius}; Transport {ECO:0000256|HAMAP-Rule:MF_00633}.
FT TRANSMEM 39..65
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT TRANSMEM 95..113
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT TRANSMEM 125..145
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT TRANSMEM 190..213
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT DOMAIN 11..222
FT /note="Cytochrome b/b6 N-terminal region profile"
FT /evidence="ECO:0000259|PROSITE:PS51002"
FT BINDING 42
FT /ligand="heme c"
FT /ligand_id="ChEBI:CHEBI:61717"
FT /note="covalent"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 93
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 107
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 194
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 209
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
SQ SEQUENCE 222 AA; 25168 MW; 2B7FE538D6FB1782 CRC64;
MFSKQVTDSK TFQWFDERLE IQAISDDITS KYVPPHVNIF YCLGGITLVC FLIQFATGFC
MTFYYKPNVA EAFTSVEYIM NEVSFGWLIR SIHRWSASMM VLMMILHTFR VYLTGGFKKP
RELTWITGVI MAVLTVSFGV TGYSLPWDQV GYWAVKIVSG VPAAIPVVGD QMVELLRGGA
SVGQATLTRF YSLHTFVLPW LIAVFMLLHF LMIRKQGISG PL
//
