Homologous Superfamily

Di-haem cytochrome, transmembrane (IPR016174)

Short name: Di-haem_cyt_TM

Overlapping entries


This entry represents a haem-binding domain with a 4-helical bundle structure that is found in transmembrane di-haem cytochromes. The domain contains four transmembrane helices in an up-and-down bundle, and binds two haem groups in between the helices; three of the four haem-binding residues is conserved between family members. Proteins containing this domain include:

  • N-terminal domain of mitochondrial cytochrome b subunit, in which the domain contains an extra transmembrane linker helix that is absent in plant and cyanobacteria subunits [PMID: 16024040].
  • Cytochrome b6 subunit of the cytochrome b6f complex, which provides the electronic connection between the photosystems I and II reaction centres of oxygenic photosynthesis, and generates a transmembrane electrochemical proton gradient for adenosine triphosphate synthesis [PMID: 14526088].
  • Cytochrome gamma subunit of formate dehydrogenase-N (Fdn-N), which acts as a major component of Escherichia coli nitrate respiration [PMID: 11884747].

Please note, this entry also identifies a number of proteins that are cleaved into two chains - a truncated non-functional cytochrome oxidase 1 and an intron-encoded endonuclease.

GO terms

Biological Process

GO:0022904 respiratory electron transport chain

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.