SIMIBI class G3E GTPase, ArgK/MeaB (IPR005129)

Short name: GTPase_ArgK

Overlapping homologous superfamilies

Family relationships



Structurally, ArgK (also known as YgfD) belongs to the G3E family of P-loop GTPases, a family defined by the glutamate residue in the Walker B motif and an intact NKxD, members of which include: UreG, HypB, CobW, and MeaB [PMID: 18950999].

ArgK is involved in the transport of positively charged amino acids (lysine, arginine, and ornithine) and has arginine kinase activity. It is found in a small, but phylogenetically diverse array of bacteria and archaea, and in Caenorhabditis and Leishmania among the eukaryotes [PMID: 11916378]. Although ArgK was characterised as an ATPase originally [PMID: 9733684], it has been shown to binds and cleaves GTP. Therefore, its actual substrate in vivo is GTP rather than ATP [PMID: 18950999].

This entry also includes methylmalonic aciduria type A (MMAA), which is associated with the fatal disease methylmalonyl aciduria [PMID: 25832174]. Caenorhabditis elegan MMAA may have a role in propionyl-CoA metabolism and adenosylcobalamin synthesis [PMID: 16843692]. The structure of MMAA has been revealed [PMID: 25832174].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005525 GTP binding
GO:0003924 GTPase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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