Family

Pyrophosphate-energised proton pump (IPR004131)

Short name: PPase-energised_H-pump

Overlapping homologous superfamilies

None.

Family relationships

None.

Description

Two types of proteins that hydrolyse inorganic pyrophosphate (PPi), very different in both amino acid sequence and structure, have been characterised to date: soluble and membrane-bound proton-pumping pyrophosphatases (sPPases and H(+)-PPases, respectively). sPPases are ubiquitous proteins that hydrolyse PPi to release heat, whereas H+-PPases, so far unidentified in animal and fungal cells, couple the energy of PPi hydrolysis to proton movement across biological membranes [PMID: 12451180, PMID: 10523139]. The latter type is represented by this group of proteins. H+-PPases (EC:3.6.1.1) are also called vacuolar-type inorganic pyrophosphatases (V-PPase) or pyrophosphate-energised vacuolar membrane proton pumps [PMID: 11343697]. In plants, vacuoles contain two enzymes for acidifying the interior of the vacuole, the V-ATPase and the V-PPase (V is for vacuolar) [PMID: 10523139].

Two distinct biochemical subclasses of H+-PPases have been characterised to date: K+-stimulated and K+-insensitive [PMID: 12451180, PMID: 11343697].

GO terms

Biological Process

GO:1902600 proton transmembrane transport

Molecular Function

GO:0009678 hydrogen-translocating pyrophosphatase activity
GO:0004427 inorganic diphosphatase activity

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
TIGRFAMs
PIRSF
Pfam
HAMAP
PANTHER