Fructose-1,6-bisphosphatase, class V (IPR002803)

Short name: FBPase_V

Overlapping homologous superfamilies

Family relationships



Fructose-1,6-bisphophatase (FBPase) catalyses the hydrolysis of D-fructose-1,6-bisphosphate (FBP) to D-fructose-6-phopshate (F6P) and orthophosphate, and is a key enzyme in gluconeogenesis [PMID: 9452458]. Three different groups of FBPases have been identified in eukaryotes and bacteria (FBPase I-III) [PMID: 10986273]. None of these groups have been found in archaea so far, though a new group of FBPases (FBPase IV) which also show inositol monophosphatase activity has recently been identified in archaea [PMID: 11062561].

Proteins in this entry are though to represent a new group of FBPases (FBPase V) which are found in thermophilic archaea and a hyperthermophilic bacterium Aquifex aeolicus [PMID: 12065581]. The characterised members of this group show strict substrate specificity for FBP and are suggested to be the true FBPase in these organisms [PMID: 12065581, PMID: 15274916]. A structural study suggests that FBPase V has a novel fold for a sugar phosphatase, forming a four-layer alpha-beta-beta-alpha sandwich, unlike the more usual five-layered alpha-beta-alpha-beta-alpha arrangement [PMID: 15274916]. The arrangement of the catalytic side chains and metal ligands was found to be consistent with the three-metal ion assisted catalysis mechanism proposed for other FBPases.

Contributing signatures

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