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alpha-helical ferredoxin superfamily
SCOP classification
InterPro annotation
| Cross references | IPR009051 SSF46548 Protein matches |
| Abstract | The alpha-helical ferredoxin domain contains two Fe4-S4 clusters, typical of bacterial ferredoxin. Iron-sulphur proteins play an important role in electron transfer processes and in various enzymatic reactions. In eukaryotes, the mitochondria are the major site of Fe-S cluster biosynthesis in the cell, used for the assembly of mitochondrial and non-mitochondrial Fe-S proteins. The alpha-helical ferredoxin domain is present in several proteins involved in redox reactions, including the C-terminal of the respiratory proteins succinate dehydrogenase (SQR) in bacteria/mitochondria, and fumarate reductase (QFR) in bacteria. SQR is analogous to the mitochondrial respiratory complex II, and is involved in the electron transport pathway from succinate as a donor to the acceptor ubiquinone. SQR helps prevent the formation of reactive oxygen species and is used during aerobic respiration, whereas QFR does not and, consequently, is used to catalyse the final step of anaerobic respiration using the acceptor fumarate [ 11850430].
The alpha-helical ferredoxin domain is also present in the N-terminal of the cytosolic protein dihydropyrimidine dehydrogenase, (DPD) which catalyses the NADPH-dependent, rate-limiting step in pyrimidine degradation, converting pyrimidines to 5,6-dihydro compounds [ 11796730]. DPD catalysis involves electron transfer from NADPH to the substrate via the Fe4-S4 centre and FAD. In mammals, this pathway produces the neurotransmitter beta-alanine. |
InterPro database
Functional annotation
| General category | Metabolism |
| Detailed category | Redox |
Function annotation of SCOP domain superfamilies
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Internal database links
The SUPERFAMILY hidden Markov model library has been used to carry
out SCOP domain assignments to all genomes at the superfamily level. Click on the 'Genome Assignments'
icon above to view the genome assignments for this superfamily.
Alignments of sequences to Alignments of sequences to 4 models
in this superfamily are available by clicking on the superfamily level 'Alignments' icon above. PDB sequences less than 40% identical
are shown by default, but any other sequences may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own.
It is possible to browse and view the proteins in the genomes which have
different combinations of domains including a alpha-helical ferredoxin domain. Click on the 'Domain Combinations' icon.
To view the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom click on the 'TaxViz' icon above. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.
Undirected domain occurrence networks are available for all superfamilies. Nodes in these networks represent genomes. Connections between nodes represent the presence of domain architectures, which contain the superfamily of interest, in both genomes.
There are 4 hidden Markov models representing the alpha-helical ferredoxin superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be viewed by clicking on the icon above.
Jump to [ Top of page · SCOP classification · InterPro annotation · Functional annotation · Internal database links ]
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