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Cytochrome f, large domain superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   All beta proteins [ 48724] (174)
Fold:   Common fold of diphtheria toxin/transcription factors/cytochrome f [ 49379] (10)
Superfamily:   Cytochrome f, large domain [ 49441]
Families:   Cytochrome f, large domain [ 49442]

Superfamily statistics
Genomes (119) Uniprot 2018_03 genome PDB chains (SCOP 1.75)
Domains 238 4,822 11
Proteins 235 4,809 11

Functional annotation
General category Metabolism
Detailed category E- transfer

Function annotation of SCOP domain superfamilies

InterPro annotation
Cross references IPR002325 SSF49441 Protein matches
Abstract The cytochrome b6f integral membrane protein complex transfers electrons between the two reaction centre complexes of oxygenic photosynthetic membranes, and participates in formation of the transmembrane electrochemical proton gradient by also transferring protons from the stromal to the internal lumen compartment. The cytochrome b6f complex contains four polypeptides: cytochrome f (285 aa); cytochrome b6 (215 aa); Rieske iron-sulphur protein (179 aa); and subunit IV (160 aa) [PubMed8027021]. In its structure and functions, the cytochrome b6f complex bears extensive analogy to the cytochrome bc1 complex of mitochondria and photosynthetic purple bacteria; cytochrome f (cyt f) plays a role analogous to that of cytochrome c1, in spite of their different structures [PubMed7631417].

The 3D structure of Brassica rapa (Turnip) cyt f has been determined [PubMed8762139]. The lumen-side segment of cyt f includes two structural domains: a small one above a larger one that, in turn, is on top of the attachment to the membrane domain. The large domain consists of an anti-parallel beta-sandwich and a short haem-binding peptide, which form a three-layer structure. The small domain is inserted between beta-strands F and G of the large domain and is an all-beta domain. The haem nestles between two short helices at the N-terminus of cyt f. Within the second helix is the sequence motif for the c-type cytochromes, CxxCH (residues 21-25), which is covalently attached to the haem through thioether bonds to Cys-21 and Cys-24. His-25 is the fifth haem iron ligand. The sixth haem iron ligand is the alpha-amino group of Tyr-1 in the first helix [PubMed8762139]. Cyt f has an internal network of water molecules that may function as a proton wire [PubMed8762139]. The water chain appears to be a conserved feature of cyt f.

InterPro database

PDBeMotif information about ligands, sequence and structure motifs
Cross references PDB entries
Ligand binding statistics
Nucleic-acid binding statistics
Occurrence of secondary structure elements
Occurrence of small 3D structural motifs

PDBeMotif resource

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Internal database links

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level.

Alignments of sequences to 5 models in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.

Browse and view proteins in genomes which have different domain combinations including a Cytochrome f, large domain domain.

Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.

Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.

There are 5 hidden Markov models representing the Cytochrome f, large domain superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.

Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Internal database links ]