CYB6_MASLA
ID CYB6_MASLA Reviewed; 215 AA.
AC P83791;
DT 13-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT 15-MAR-2004, sequence version 1.
DT 03-AUG-2022, entry version 97.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Mastigocladus laminosus (Fischerella sp.).
OC Bacteria; Cyanobacteria; Nostocales; Hapalosiphonaceae; Mastigocladus.
OX NCBI_TaxID=83541;
RN [1]
RP HEME-BINDING.
RX PubMed=12438564; DOI=10.1074/mcp.m200045-mcp200;
RA Whitelegge J.P., Zhang H., Aguilera R., Taylor R.M., Cramer W.A.;
RT "Full subunit coverage liquid chromatography electrospray ionization mass
RT spectrometry (LCMS+) of an oligomeric membrane protein: cytochrome b(6)f
RT complex from spinach and the cyanobacterium Mastigocladus laminosus.";
RL Mol. Cell. Proteomics 1:816-827(2002).
RN [2]
RP X-RAY CRYSTALLOGRAPHY (3.0 ANGSTROMS) IN COMPLEX WITH HEME IN CYTOCHROME
RP B6-F COMPLEX, FUNCTION, COFACTOR, SUBUNIT, SUBCELLULAR LOCATION, AND
RP TOPOLOGY.
RX PubMed=14526088; DOI=10.1126/science.1090165;
RA Kurisu G., Zhang H., Smith J.L., Cramer W.A.;
RT "Structure of the cytochrome b6f complex of oxygenic photosynthesis: tuning
RT the cavity.";
RL Science 302:1009-1014(2003).
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:0000305|PubMed:14526088}.
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000269|PubMed:12438564, ECO:0000269|PubMed:14526088};
CC Note=Binds 2 heme groups. One heme group is bound covalently by a
CC single cysteine link, the other one non-covalently.
CC {ECO:0000269|PubMed:14526088};
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:0000269|PubMed:14526088}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane
CC {ECO:0000305|PubMed:14526088}; Multi-pass membrane protein
CC {ECO:0000269|PubMed:14526088}.
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 PDB; 1VF5; X-ray; 3.00 A; A/N=1-215.
DR PDB; 2D2C; X-ray; 3.80 A; A/N=1-215.
DR PDB; 2E74; X-ray; 3.00 A; A=1-215.
DR PDB; 2E75; X-ray; 3.55 A; A=1-215.
DR PDB; 2E76; X-ray; 3.41 A; A=1-215.
DR PDB; 4H0L; X-ray; 3.25 A; A=1-215.
DR PDB; 4H13; X-ray; 3.07 A; A=1-215.
DR PDB; 4I7Z; X-ray; 2.80 A; A=1-215.
DR PDB; 4PV1; X-ray; 3.00 A; A=1-215.
DR PDBsum; 1VF5; -.
DR PDBsum; 2D2C; -.
DR PDBsum; 2E74; -.
DR PDBsum; 2E75; -.
DR PDBsum; 2E76; -.
DR PDBsum; 4H0L; -.
DR PDBsum; 4H13; -.
DR PDBsum; 4I7Z; -.
DR PDBsum; 4PV1; -.
DR AlphaFoldDB; P83791; -.
DR SMR; P83791; -.
DR DrugBank; DB08453; 2-Nonyl-4-quinolinol 1-oxide.
DR DrugBank; DB04646; Dibromothymoquinone.
DR BRENDA; 7.1.1.6; 7666.
DR EvolutionaryTrace; P83791; -.
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 1: Evidence at protein level;
KW 3D-structure; Electron transport; Heme; Iron; Membrane; Metal-binding;
KW Photosynthesis; Thylakoid; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000061827"
FT TOPO_DOM 1..31
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:14526088"
FT TRANSMEM 32..52
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633,
FT ECO:0000305|PubMed:14526088"
FT TOPO_DOM 53..89
FT /note="Lumenal, thylakoid"
FT /evidence="ECO:0000305|PubMed:14526088"
FT TRANSMEM 90..110
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633,
FT ECO:0000305|PubMed:14526088"
FT TOPO_DOM 111..115
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:14526088"
FT TRANSMEM 116..136
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633,
FT ECO:0000305|PubMed:14526088"
FT TOPO_DOM 137..185
FT /note="Lumenal, thylakoid"
FT /evidence="ECO:0000305|PubMed:14526088"
FT TRANSMEM 186..206
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633,
FT ECO:0000305|PubMed:14526088"
FT TOPO_DOM 207..215
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305|PubMed:14526088"
FT BINDING 35
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /note="covalent"
FT /evidence="ECO:0000269|PubMed:14526088"
FT BINDING 86
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:0000269|PubMed:14526088"
FT BINDING 100
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:0000269|PubMed:14526088"
FT BINDING 187
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:0000269|PubMed:14526088"
FT BINDING 202
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:0000269|PubMed:14526088"
FT HELIX 4..12
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 15..23
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 32..35
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 36..54
FT /evidence="ECO:0007829|PDB:4I7Z"
FT TURN 55..57
FT /evidence="ECO:0007829|PDB:4I7Z"
FT TURN 62..64
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 65..74
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 79..105
FT /evidence="ECO:0007829|PDB:4I7Z"
FT TURN 106..110
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 112..114
FT /evidence="ECO:0007829|PDB:2E74"
FT HELIX 115..136
FT /evidence="ECO:0007829|PDB:4I7Z"
FT TURN 137..139
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 142..151
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 152..157
FT /evidence="ECO:0007829|PDB:4I7Z"
FT TURN 159..161
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 162..170
FT /evidence="ECO:0007829|PDB:4I7Z"
FT STRAND 172..174
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 177..188
FT /evidence="ECO:0007829|PDB:4I7Z"
FT HELIX 190..209
FT /evidence="ECO:0007829|PDB:4I7Z"
SQ SEQUENCE 215 AA; 24227 MW; 4FDCD9336CD31642 CRC64;
MANVYDWFQE RLEIQALADD VTSKYVPPHV NIFYCLGGIT LTCFLIQFAT GFAMTFYYKP
TVTEAYASVQ YIMNEVSFGW LIRSIHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWIS
GVILAVITVS FGVTGYSLPW DQVGYWAVKI VSGVPEAIPV VGVLISDLLR GGSSVGQATL
TRYYSAHTFV LPWLIAVFML LHFLMIRKQG ISGPL
