InterPro domain: IPR005854

Purine nucleotides are synthesised both via the de novo pathway and via the salvage pathway and are vital for cell functions and cell proliferation through DNA and RNA syntheses and ATP energy supply. Amidophosphoribosyltransferase ( 2.4.2.14 ) is the rate-limiting enzyme in the de novo pathway of purine ribonucleotide synthesis and is regulated by feedback inhibition by AMP and GMP [ 1 ]. 5-phospho-beta-D-ribosylamine + diphosphate + L-glutamate = L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O

This family contains sequences which are members of the MEROPS peptidase family C44 (glutamine phosphoribosylpyrophosphate amidotransferase precursor, clan PB(C)) and sequences which are classed as non-peptidase homologues. These are sequences either have been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for the catalytic activity.

1. Feedback inhibition of amidophosphoribosyltransferase regulates the rate of cell growth via purine nucleotide, DNA, and protein syntheses. J. Biol. Chem. 276, 21285-91