CYB6_PROM9
ID CYB6_PROM9 Reviewed; 218 AA.
AC Q31CK3;
DT 05-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT 06-DEC-2005, sequence version 1.
DT 03-AUG-2022, entry version 108.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
GN OrderedLocusNames=PMT9312_0331;
OS Prochlorococcus marinus (strain MIT 9312).
OC Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC Prochlorococcus.
OX NCBI_TaxID=74546;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=MIT 9312;
RG US DOE Joint Genome Institute;
RA Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T.,
RA Hammon N., Israni S., Pitluck S., Thiel J., Schmutz J., Larimer F.,
RA Land M., Kyrpides N., Lykidis A., Richardson P.;
RT "Complete sequence of Prochlorococcus marinus str. MIT 9312.";
RL Submitted (JUL-2005) 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:0000255|HAMAP-Rule:MF_00633}.
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00633};
CC Note=Binds 2 heme groups. One heme group is bound covalently by a
CC single cysteine link, the other one non-covalently. {ECO:0000255|HAMAP-
CC 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:0000255|HAMAP-
CC Rule:MF_00633}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000255|HAMAP-
CC Rule:MF_00633}; Multi-pass membrane protein {ECO:0000255|HAMAP-
CC Rule:MF_00633}.
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:0000255|HAMAP-Rule:MF_00633}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily.
CC {ECO:0000255|HAMAP-Rule:MF_00633}.
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DR EMBL; CP000111; ABB49392.1; -; Genomic_DNA.
DR RefSeq; WP_011375892.1; NC_007577.1.
DR AlphaFoldDB; Q31CK3; -.
DR SMR; Q31CK3; -.
DR STRING; 74546.PMT9312_0331; -.
DR EnsemblBacteria; ABB49392; ABB49392; PMT9312_0331.
DR KEGG; pmi:PMT9312_0331; -.
DR eggNOG; COG1290; Bacteria.
DR HOGENOM; CLU_031114_0_2_3; -.
DR OMA; WATQTGM; -.
DR OrthoDB; 1339825at2; -.
DR Proteomes; UP000002715; Chromosome.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
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 Gene3D; 1.20.810.10; -; 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; IPR016174; Di-haem_cyt_TM.
DR PANTHER; PTHR19271:SF20; PTHR19271:SF20; 1.
DR Pfam; PF00033; Cytochrome_B; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 3: Inferred from homology;
KW Electron transport; Heme; Iron; Membrane; Metal-binding; Photosynthesis;
KW Thylakoid; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..218
FT /note="Cytochrome b6"
FT /id="PRO_1000061412"
FT TRANSMEM 35..55
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 93..113
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 119..139
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 189..209
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 38
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /note="covalent"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 89
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 103
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 190
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 205
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
SQ SEQUENCE 218 AA; 24644 MW; A38FC75C62BB24FD CRC64;
MANSSSVYDW FQERLEIQDI TDDVTSKYVP PHVNIFYCLG GITLVCFLIQ FATGFAMTFY
YKPTVTQAYN SVSYLMTDVS FGWLIRSVHR WSASMMVLML ILHVFRVYLT GGFKRPRELT
WVTGVVMAVI TVAFGVTGYS LPWDQVGYWA VKIVSGVPAA IPVIGDFMVE LLRGGESVGQ
STLTRFYSLH TFVLPWSLAV FMLMHFLMIR KQGISGPL
