CYB6_HELMO
ID CYB6_HELMO Reviewed; 213 AA.
AC Q9ZGG0;
DT 11-APR-2003, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-1999, sequence version 1.
DT 03-AUG-2022, entry version 98.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
GN Synonyms=cytB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Heliobacterium mobile (Heliobacillus mobilis).
OC Bacteria; Firmicutes; Clostridia; Eubacteriales; Heliobacteriaceae;
OC Heliobacterium.
OX NCBI_TaxID=28064;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=9843979; DOI=10.1073/pnas.95.25.14851;
RA Xiong J., Inoue K., Bauer C.E.;
RT "Tracking molecular evolution of photosynthesis by characterization of a
RT major photosynthesis gene cluster from Heliobacillus mobilis.";
RL Proc. Natl. Acad. Sci. U.S.A. 95:14851-14856(1998).
CC -!- FUNCTION: Component of the cytochrome bc complex which donates
CC electrons to the photosynthetic reaction center. {ECO:0000255|HAMAP-
CC 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 subunits of the cytochrome bc complex are a Rieske Fe-S
CC protein (PetC), cytochrome b6 (PetB), subunit IV (PetD), and a diheme
CC cytochrome c (PetX). {ECO:0000255|HAMAP-Rule:MF_00633}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000255|HAMAP-Rule:MF_00633};
CC Multi-pass membrane protein {ECO:0000255|HAMAP-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}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; AF080002; AAC84019.1; -; Genomic_DNA.
DR PIR; T31447; T31447.
DR AlphaFoldDB; Q9ZGG0; -.
DR SMR; Q9ZGG0; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005886; C:plasma 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 Pfam; PF00033; Cytochrome_B; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 3: Inferred from homology;
KW Cell membrane; Electron transport; Heme; Iron; Membrane; Metal-binding;
KW Photosynthesis; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..213
FT /note="Cytochrome b6"
FT /id="PRO_0000061840"
FT TRANSMEM 30..50
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 88..108
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 114..134
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 184..204
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 33
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 84
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 98
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 185
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 200
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 213 AA; 23712 MW; 99ABE0FF48CE8804 CRC64;
MNWLEERLPG IGKVAEDIAE HPVPSHTLNI FYCLGGLTLL AFLVQCVTGL FLALYYKPTP
EAAFASVQMI TNEVRFGATI RSLHHWAANL MILLVFLHML RVYYTGSFKK PRELNWLAGC
FLLVLSLGLA FTGYLLPYEQ LSYWASVIGA ETAGSLPVVG ATMKIMMQGG IKVTAEMLSR
FYVLHVMILP LVTIGFLVAH FIMIRVQGIS DPM
