HAMAP rule MF_00633
General rule information
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| Accession | MF_00633 |
| Dates | 4-APR-2003 (Created)
15-MAY-2023 (Last updated, Version 55) |
| Name | Cytb6_f_cytb6 |
| Scope(s) |
Bacteria Cyanobacteriota Heliobacteriaceae Plastid |
| Template(s) | Q00471 (CYB6_CHLRE); P00165 (CYB6_SPIOL); P83791 (CYB6_MASLA); Q57038 (CYB6_SYNY3); [ Recover all ] |
| Triggered by |
HAMAP; MF_00633 (Get profile general information and statistics) |
Propagated annotation
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Identifier, protein and gene names
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| Identifier | CYB6 |
| Protein name | RecName: Full=Cytochrome b6; |
| case not <OC:Heliobacteriaceae> | |
| Gene name | Name=petB; |
| else case <OC:Heliobacteriaceae> | |
| Gene name | Name=petB; Synonyms=cytB; |
| end case | |
Comments
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| case <OC:Heliobacteriaceae> | |
| FUNCTION | Component of the cytochrome bc complex which donates electrons to the photosynthetic reaction center. |
| COFACTOR | Name=heme b; Xref=ChEBI:CHEBI:60344; Note=Binds 2 heme b groups non-covalently with two histidine residues as axial ligands. |
| COFACTOR | Name=heme c; Xref=ChEBI:CHEBI:61717; Note=Binds one heme group covalently by a single cysteine link with no axial amino acid ligand. This heme was named heme ci. |
| SUBUNIT | The subunits of the cytochrome bc complex are a Rieske Fe-S protein (PetC), cytochrome b6 (PetB), subunit IV (PetD), and a diheme cytochrome c (PetX). |
| else case not <OC:Heliobacteriaceae> | |
| FUNCTION | Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions. |
| COFACTOR | Name=heme b; Xref=ChEBI:CHEBI:60344; Note=Binds 2 heme b groups non-covalently with two histidine residues as axial ligands. |
| COFACTOR | Name=heme c; Xref=ChEBI:CHEBI:61717; Note=Binds one heme group covalently by a single cysteine link with no axial amino acid ligand. This heme was named heme ci. |
| SUBUNIT | The 4 large subunits of the cytochrome b6-f complex are cytochrome b6, subunit IV (17 kDa polypeptide, PetD), cytochrome f and the Rieske protein, while the 4 small subunits are PetG, PetL, PetM and PetN. The complex functions as a dimer. |
| end case | |
| case <OC:Heliobacteriaceae> | |
| SUBCELLULAR LOCATION | Cell membrane; Multi-pass membrane protein. |
| else case <OG:Chloroplast> | |
| SUBCELLULAR LOCATION | Plastid, chloroplast thylakoid membrane; Multi- pass membrane protein. |
| else case <OC:Gloeobacter> | |
| SUBCELLULAR LOCATION | Cell inner membrane; Multi-pass membrane protein. |
| else | |
| SUBCELLULAR LOCATION | Cellular thylakoid membrane; Multi-pass membrane protein. |
| end case | |
| MISCELLANEOUS | Heme 1 (or BH or b566) is high-potential and absorbs at about 566 nm, and heme 2 (or BL or b562) is low-potential and absorbs at about 562 nm. |
| SIMILARITY | Belongs to the cytochrome b family. PetB subfamily. |
Keywords
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| Transport | |
| Electron transport | |
| Photosynthesis | |
| case <OC:Gloeobacter> | |
| Cell membrane | |
| Cell inner membrane | |
| else case <OG:Chloroplast> or <Property:Thylakoid> | |
| Thylakoid | |
| else case <OC:Heliobacteriaceae> | |
| Cell membrane | |
| end case | |
| Membrane | |
| Heme | |
| Metal-binding | |
| Iron | |
| Transmembrane | |
| Transmembrane helix | |
Gene Ontology
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| case <OCellular component:Heliobacteriaceae> or <OC:Gloeobacter> | |
| GO:0005886; Cellular component:plasma membrane | |
| else case <OG:Chloroplast> | |
| GO:0009535; Cellular component:chloroplast thylakoid membrane | |
| else; https://www.ebi.ac.uk/QuickGO/term/else | |
| GO:0042651; Cellular component:thylakoid membrane | |
| end case | |
| GO:0045158; Molecular function:electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity | |
| GO:0015979; Biological process:photosynthesis | |
Cross-references
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Features
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| From: CYB6_CHLRE (Q00471) | ||||||||||||
| Key | From | To | Description | Tag | Condition | FTGroup | ||||||
| TRANSMEM | 32 | 52 | /note="Helical" | |||||||||
| TRANSMEM | 90 | 110 | /note="Helical" | |||||||||
| TRANSMEM | 116 | 136 | /note="Helical" | |||||||||
| TRANSMEM | 186 | 206 | /note="Helical" | |||||||||
| BINDING | 35 | 35 | /ligand="heme c" /ligand_id="ChEBI:CHEBI:61717" /note="covalent" |
C | ||||||||
| BINDING | 86 | 86 | /ligand="heme b" /ligand_id="ChEBI:CHEBI:60344" /ligand_label="2" /ligand_part="Fe" /ligand_part_id="ChEBI:CHEBI:18248" /note="axial binding residue" |
H | ||||||||
| BINDING | 100 | 100 | /ligand="heme b" /ligand_id="ChEBI:CHEBI:60344" /ligand_label="1" /ligand_part="Fe" /ligand_part_id="ChEBI:CHEBI:18248" /note="axial binding residue" |
H | ||||||||
| BINDING | 187 | 187 | /ligand="heme b" /ligand_id="ChEBI:CHEBI:60344" /ligand_label="2" /ligand_part="Fe" /ligand_part_id="ChEBI:CHEBI:18248" /note="axial binding residue" |
H | ||||||||
| BINDING | 202 | 202 | /ligand="heme b" /ligand_id="ChEBI:CHEBI:60344" /ligand_label="1" /ligand_part="Fe" /ligand_part_id="ChEBI:CHEBI:18248" /note="axial binding residue" |
H | ||||||||
Additional information
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| Size range | 213-222 amino acids |
| Related rules |
None |
| Fusion | Nter: None Cter: None |
| Comments | In maize and tobacco position 204 has been shown to undergo RNA editing to change the codon from Pro to Leu. It has therefore been suggested to occur in all other plants where this codon is Pro (CCA -> CTA). In C.reinhardtii an engineered Pro mutation at this position is unable to assemble intact complex, giving strength to this suggestion. |