ribose-phosphate pyrophosphokinase 2; PPribP; phosphoribosyl pyrophosphate synthase II; PRS-II (PRPS2)

Function

• catalyzes synthesis of phosphoribosylpyrophosphate (PRPP), essential for nucleotide synthesis
• activated by Mg+2 & inorganic phosphate
• metabolic intermediate biosynthesis; 5-phospho-alpha-D-ribose-1-pyrophosphate biosynthesis; 5-phospho-alpha-D-ribose-1-pyrophosphate from D-ribose 5-phosphate (route I): step 1/1

ATP + D-ribose 5-phosphate = AMP + 5-phospho-alpha-D-ribose 1-pyrophosphate

Inhibition:

• competitively or non-competitively inhibited by ADP, 2,3-bisphosphoglyceride or GDP

Cofactor: Mg+2

Structure

• homodimer
• the active form is probably an hexamer composed of 3 homodimers (putative)
• belongs to the ribose-phosphate pyrophosphokinase family

Alternative splicing

named isoforms=2

More general terms

• phosphoribosyl pyrophosphate synthetase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5634
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5634
• OMIM: https://mirror.omim.org/entry/311860
• UniProt: http://www.uniprot.org/uniprot/P11908.html