phosphoribosyl pyrophosphate [PRPP] synthetase; ribosephosphate pyrophosphokinase

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-diphosphate biosynthesis; 5-phospho-alpha-D-ribose 1-diphosphate from D-ribose 5-phosphate (route I): step 1/1

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

Cofactor: Mg+2

Structure

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

Pathology

• PRPP synthetase deficiency
• PRPP synthetase overactivity leads to hyperuricemia

Laboratory

• phophoribosylpyrophosphate synthetase in fibroblasts
• phophoribosylpyrophosphate synthetase in erythrocytes

More general terms

• kinase or ATP-phosphotransferase

More specific terms

• ribose-phosphate pyrophosphokinase 1; PPribP; phosphoribosyl pyrophosphate synthase 1; PRS-1 (PRPS1)
• ribose-phosphate pyrophosphokinase 2; PPribP; phosphoribosyl pyrophosphate synthase II; PRS-II (PRPS2)
• ribose-phosphate pyrophosphokinase 3; phosphoribosyl pyrophosphate synthase 1-like 1; PRPS1-like 1; phosphoribosyl pyrophosphate synthase 3; PRS-3 (PRPS1L1, PRPS3, PRPSL)