ACT domain (IPR002912)

Short name: ACT_dom

Overlapping homologous superfamilies


Domain relationships


The ACT domain is found in a variety of contexts and is proposed to be a conserved regulatory binding fold. ACT domains are linked to a wide range of metabolic enzymes that are regulated by amino acid concentration. The archetypical ACT domain is the C-terminal regulatory domain of 3-phosphoglycerate dehydrogenase (3PGDH), which folds with a ferredoxin-like topology. A pair of ACT domains form an eight-stranded antiparallel sheet with two molecules of allosteric inhibitor serine bound in the interface. Biochemical exploration of a few other proteins containing ACT domains supports the suggestions that these domains contain the archetypical ACT structure [PMID: 11751050].

Most of the proteins in which it is found are involved in amino acid and purine metabolism:

  • aspartokinases
  • chorismate mutases
  • prephenate dehydrogenases (TyrA)
  • prephenate dehydratases
  • homoserine dehydrogenases
  • malate dehydrogenases
  • phosphoglycerate dehydrogenases
  • phenylalanine and tryptophan-4-monooxygenases
  • phosphoribosylformylglycinamidine synthase (PurQ)
  • uridylyl transferase and removing enzyme (GlnD)
  • GTP pyrophosphokinase/phosphohydrolase (SpoT/RelA)
  • tyrosine and phenol metabolism operon regulators (TyrR)
  • several uncharacterised proteins from archaea, bacteria and plants that contain from one to four copies of this domain [PMID: 12481063].

Contributing signatures

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