UbiB domain, ADCK3-like (IPR034646)

Short name: ADCK3_UbiB

Overlapping homologous superfamilies

Domain relationships

  • UbiB domain (IPR004147)
    • UbiB domain, ADCK3-like (IPR034646)


UbiB kinases are present in archaea, bacteria and eukaryote. The founding member of the UbiB family, UbiB from Escherichia coli, is required for the aerobic biosynthesis of coenzyme Q (CoQ). In eukaryotes, UbiB homologues are found exclusively in mitochondria and plastids. This entry represents the UbiB domain found in eukaryotes and some bacteria, but not in E. coli and related species [PMID: 25498144].

This domain is found in the atypical yeast protein kinase Abc1p (also called Coq8p), its human homologue ADCK3 (also called COQ8A), and similar proteins. Abc1p is required for the biosynthesis of Coenzyme Q (ubiquinone or Q), which is an essential lipid component in respiratory electron and proton transport. It is necessary for the formation of a multi-subunit Q-biosynthetic complex and may also function in the regulation of Q synthesis. Human ADCK3 is able to rescue defects in Q synthesis and the phosphorylation state of Coq proteins in yeast Abc1 (or Coq8) mutants [PMID: 21296186]. Mutations in ADCK3 cause progressive cerebellar ataxia and atrophy due to Q10 deficiency [PMID: 22036850, PMID: 20580948, PMID: 18319074, PMID: 18319072].

In algae and higher plants, ABC1 kinases have proliferated to more than 15 subfamilies, most of which are located in plastids or mitochondria [PMID: 22694836, PMID: 22548231]. Subfamily 13 (ABC1K13) of plant ABC1 kinases belongs in this group with yeast Abc1p and human ADCK3. ABC1 kinases are not related to the ATP-binding cassette (ABC) membrane transporter family.

Contributing signatures

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