CYB6_CHLRE
ID CYB6_CHLRE Reviewed; 215 AA.
AC Q00471; B7U1F1;
DT 01-DEC-1992, integrated into UniProtKB/Swiss-Prot.
DT 01-DEC-1992, sequence version 1.
DT 03-AUG-2022, entry version 146.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Chlamydomonas reinhardtii (Chlamydomonas smithii).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Chlorophyta; core chlorophytes; Chlorophyceae;
OC CS clade; Chlamydomonadales; Chlamydomonadaceae; Chlamydomonas.
OX NCBI_TaxID=3055;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=137c / CC-125;
RX PubMed=2060646; DOI=10.1016/0014-5793(91)80698-3;
RA Bueschlen S., Choquet Y., Kuras R., Wollman F.A.;
RT "Nucleotide sequences of the continuous and separated petA, petB and petD
RT chloroplast genes in Chlamydomonas reinhardtii.";
RL FEBS Lett. 284:257-262(1991).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=1581576; DOI=10.1007/bf00019214;
RA Huang C., Liu X.-Q.;
RT "Nucleotide sequence of the frxC, petB and trnL genes in the chloroplast
RT genome of Chlamydomonas reinhardtii.";
RL Plant Mol. Biol. 18:985-988(1992).
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CC-503;
RX PubMed=19473533; DOI=10.1186/1471-2148-9-120;
RA Smith D.R., Lee R.W.;
RT "Nucleotide diversity of the Chlamydomonas reinhardtii plastid genome:
RT addressing the mutational-hazard hypothesis.";
RL BMC Evol. Biol. 9:120-120(2009).
RN [4]
RP IDENTIFICATION, AND COMPLETE PLASTID GENOME.
RX PubMed=12417694; DOI=10.1105/tpc.006155;
RA Maul J.E., Lilly J.W., Cui L., dePamphilis C.W., Miller W., Harris E.H.,
RA Stern D.B.;
RT "The Chlamydomonas reinhardtii plastid chromosome: islands of genes in a
RT sea of repeats.";
RL Plant Cell 14:2659-2679(2002).
RN [5]
RP CHARACTERIZATION.
RC STRAIN=WT12;
RX PubMed=7493968; DOI=10.1074/jbc.270.49.29342;
RA Pierre Y., Breyton C., Kramer D., Popot J.-L.;
RT "Purification and characterization of the cytochrome b6 f complex from
RT Chlamydomonas reinhardtii.";
RL J. Biol. Chem. 270:29342-29349(1995).
RN [6]
RP MUTAGENESIS OF LEU-204.
RC STRAIN=137c / CC-125;
RX PubMed=9037161; DOI=10.1023/a:1005734809834;
RA Zito F., Kuras R., Choquet Y., Koessel H., Wollman F.-A.;
RT "Mutations of cytochrome b6 in Chlamydomonas reinhardtii disclose the
RT functional significance for a proline to leucine conversion by petB editing
RT in maize and tobacco.";
RL Plant Mol. Biol. 33:79-86(1997).
RN [7]
RP HEME-BINDING.
RX PubMed=15049703; DOI=10.1021/bi036093p;
RA de Vitry C., Desbois A., Redeker V., Zito F., Wollman F.A.;
RT "Biochemical and spectroscopic characterization of the covalent binding of
RT heme to cytochrome b6.";
RL Biochemistry 43:3956-3968(2004).
RN [8]
RP X-RAY CRYSTALLOGRAPHY (3.1 ANGSTROMS) IN COMPLEX WITH HEME.
RX PubMed=14647374; DOI=10.1038/nature02155;
RA Stroebel D., Choquet Y., Popot J.-L., Picot D.;
RT "An atypical haem in the cytochrome b(6)f complex.";
RL Nature 426:413-418(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 -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000269|PubMed:14647374, ECO:0000269|PubMed:15049703};
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:14647374};
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.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane; Multi-
CC pass membrane protein.
CC -!- PTM: The N-terminus is blocked.
CC -!- MISCELLANEOUS: Creation by mutagenesis of a Pro residue at position 204
CC (a codon that is known to be RNA edited to a Leu codon in tobacco and
CC maize) leads to assembly defective mutants, indicating that the Leu-204
CC is essential for proper assembly of the cytochrome b6-f complex. This
CC is probably due to lack of assembly of apocytochrome b6 with one of its
CC heme groups. {ECO:0000269|PubMed:9037161}.
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; X62905; CAA44690.1; -; Genomic_DNA.
DR EMBL; X72918; CAA51423.1; -; Genomic_DNA.
DR EMBL; FJ423446; ACJ50098.1; -; Genomic_DNA.
DR EMBL; BK000554; DAA00911.1; -; Genomic_DNA.
DR PIR; S21253; S21253.
DR RefSeq; NP_958365.1; NC_005353.1.
DR PDB; 1Q90; X-ray; 3.10 A; B=1-215.
DR PDBsum; 1Q90; -.
DR AlphaFoldDB; Q00471; -.
DR SMR; Q00471; -.
DR DIP; DIP-58593N; -.
DR IntAct; Q00471; 9.
DR STRING; 3055.DAA00911; -.
DR PaxDb; Q00471; -.
DR PRIDE; Q00471; -.
DR GeneID; 2717017; -.
DR KEGG; cre:ChreCp008; -.
DR eggNOG; KOG4663; Eukaryota.
DR HOGENOM; CLU_031114_0_2_1; -.
DR InParanoid; Q00471; -.
DR OrthoDB; 1125966at2759; -.
DR BioCyc; MetaCyc:CHRECP008-MON; -.
DR EvolutionaryTrace; Q00471; -.
DR Proteomes; UP000006906; Chloroplast.
DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
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; Chloroplast; Electron transport; Heme; Iron; Membrane;
KW Metal-binding; Photosynthesis; Plastid; Reference proteome; Thylakoid;
KW Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000061787"
FT TRANSMEM 32..52
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 90..110
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 116..136
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 186..206
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 35
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /note="covalent"
FT /evidence="ECO:0000269|PubMed:14647374"
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:14647374"
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:14647374"
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:14647374"
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:14647374"
FT MUTAGEN 204
FT /note="L->P: Leads to defective cytochrome b6-f complex
FT assembly, probably due to lack of heme assembly."
FT /evidence="ECO:0000269|PubMed:9037161"
FT HELIX 5..12
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 14..23
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 33..35
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 36..54
FT /evidence="ECO:0007829|PDB:1Q90"
FT TURN 55..57
FT /evidence="ECO:0007829|PDB:1Q90"
FT TURN 62..64
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 65..74
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 79..105
FT /evidence="ECO:0007829|PDB:1Q90"
FT TURN 106..110
FT /evidence="ECO:0007829|PDB:1Q90"
FT STRAND 111..113
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 115..137
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 142..153
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 154..157
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 161..170
FT /evidence="ECO:0007829|PDB:1Q90"
FT STRAND 172..176
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 177..188
FT /evidence="ECO:0007829|PDB:1Q90"
FT HELIX 190..209
FT /evidence="ECO:0007829|PDB:1Q90"
SQ SEQUENCE 215 AA; 24165 MW; E025FB9ED2ED78B4 CRC64;
MSKVYDWFEE RLEIQAIADD ITSKYVPPHV NIFYCIGGIT FTCFLVQVAT GFAMTFYYRP
TVAEAFASVQ YIMTDVNFGW LIRSIHRWSA SMMVLMMVLH VFRVYLTGGF KRPRELTWVT
GVIMAVCTVS FGVTGYSLPW DQVGYWAVKI VTGVPDAIPG VGGFIVELLR GGVGVGQATL
TRFYSLHTFV LPLLTAVFML MHFLMIRKQG ISGPL
