-
Overview
Ribose-phosphate pyrophosphokinase (IPR005946)
Short name: Rib-P_diPkinase
Overlapping homologous superfamilies
- Phosphoribosyltransferase-like (IPR029057)
Family relationships
- Ribose-phosphate pyrophosphokinase (IPR005946)
- Ribose-phosphate pyrophosphokinase, archaea (IPR037514)
- Ribose-phosphate pyrophosphokinase, bacterial-type (IPR037515)
Description
Ribose-phosphate diphosphokinase, also known as ribose-phosphate pyrophosphokinase (RPPK), or phosphoribosyldiphosphate synthetase (EC:2.7.6.1), catalyses the transfer of an intact diphosphate (PP) group from ATP to ribose-5-phosphate (R-5-P), which results in the formation of AMP and 5-phospho-D-ribosyl--1-diphosphate (PRPP).
PRPP is an essential precursor for purine and pyrimidine nucleotides, both in the de novo synthesis and in the salvage pathway, as well as in the synthesis of pyridine nucleotide coenzymes. The activity of PPPK is highly regulated. Besides competitive inhibition at the substrate binding sites, most RPPKs are regulated in an allosteric manner, in which ADP generally acts as the most potent inhibitor. In some systems, close homologues lacking enzymatic activity exist and perform regulatory functions.
GO terms
Biological Process
GO:0009165 nucleotide biosynthetic process
Molecular Function
GO:0000287 magnesium ion binding
GO:0004749 ribose phosphate diphosphokinase activity
Cellular Component
No terms assigned in this category.