Ribose 5-phosphate isomerase B (IPR004785)

Short name: RpiB

Overlapping homologous superfamilies

Family relationships


Ribose 5-phosphate isomerase (EC: forms a homodimer and catalyses the interconversion of D-ribose 5-phosphate and D-ribulose 5-phosphate in the non-oxidative branch of the pentose phosphate pathway. This reaction permits the synthesis of ribose from other sugars, as well as the recycling of sugars from nucleotide breakdown. Two unrelated enzymes can catalyse this reaction: RpiA (found in most organisms) and RpiB (found in some bacteria and eukaryotes). RpiB is also involved in metabolism of the rare sugar, allose, in addition to ribose sugars. The structures of RpiA and RpiB are distinct, RpiB having a Rossmann-type alpha/beta/alpha sandwich topology [PMID: 14499611]. This entry represents the RpiB enzyme.

GO terms

Biological Process

GO:0006098 pentose-phosphate shunt

Molecular Function

GO:0004751 ribose-5-phosphate isomerase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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