5-(carboxyamino)imidazole ribonucleotide synthase

5-(carboxyamino)imidazole ribonucleotide synthase
Identifiers
EC number	6.3.4.18
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

In enzymology, a 5-(carboxyamino)imidazole ribonucleotide synthase (EC 6.3.4.18) is an enzyme that catalyzes the chemical reaction

ATP + 5-amino-1-(5-phospho-D-ribosyl)imidazole + HCO₃⁻ $\rightleftharpoons$ ADP + phosphate + 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole

The 3 substrates of this enzyme are ATP, 5-amino-1-(5-phospho-D-ribosyl)imidazole ("AIR"), and HCO₃⁻, whereas its 3 products are ADP, phosphate, and 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole.

This enzyme belongs to the family of ligases, specifically those forming generic carbon-nitrogen bonds. The systematic name of this enzyme class is 5-amino-1-(5-phospho-D-ribosyl)imidazole:carbon-dioxide ligase (ADP-forming). Other names in common use include N5-CAIR synthetase, N5-carboxyaminoimidazole ribonucleotide synthetase, and PurK.

References

• Meyer E, Leonard NJ, Bhat B, Stubbe J, Smith JM (1992). "Purification and characterization of the purE, purK, and purC gene products: identification of a previously unrecognized energy requirement in the purine biosynthetic pathway". Biochemistry. 31 (21): 5022–32. doi:10.1021/bi00136a016. PMID 1534690.
• Mueller EJ, Meyer E, Rudolph J, Davisson VJ, Stubbe J (1994). "N5-carboxyaminoimidazole ribonucleotide: evidence for a new intermediate and two new enzymatic activities in the de novo purine biosynthetic pathway of Escherichia coli". Biochemistry. 33 (8): 2269–78. doi:10.1021/bi00174a038. PMID 8117684.
• Thoden JB, Kappock TJ, Stubbe J, Holden HM (1999). "Three-dimensional structure of N5-carboxyaminoimidazole ribonucleotide synthetase: a member of the ATP grasp protein superfamily". Biochemistry. 38 (47): 15480–92. doi:10.1021/bi991618s. PMID 10569930.