Phosphoribosylaminoimidazolecarboxamide formyltransferase

In enzymology, a phosphoribosylaminoimidazolecarboxamide formyltransferase (EC 2.1.2.3), also known by the shorter name AICAR transformylase, is an enzyme that catalyzes the chemical reaction

10-formyltetrahydrofolate + AICAR ${\displaystyle \rightleftharpoons }$ tetrahydrofolate + FAICAR

phosphoribosylaminoimidazolecarboxamide formyltransferase
Identifiers
EC no.	2.1.2.3
CAS no.	9032-03-5
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are 10-formyltetrahydrofolate and AICAR, whereas its two products are tetrahydrofolate and FAICAR.

This enzyme participates in purine metabolism and one carbon pool by folate.

Nomenclature

This enzyme belongs to the family of transferases that transfer one-carbon groups, specifically the hydroxymethyl-, formyl- and related transferases. The systematic name of this enzyme class is 10-formyltetrahydrofolate:5-phosphoribosyl-5-amino-4-imidazole-carb oxamide N-formyltransferase. Other names in common use include:

• 10-formyltetrahydrofolate:5-phosphoribosyl-5-amino-4-imidazolecarboxamide formyltransferase
• 5-amino-1-ribosyl-4-imidazolecarboxamide 5-phosphate,
• 5-amino-4-imidazolecarboxamide ribonucleotide transformylase,
• 5-amino-4-imidazolecarboxamide ribotide transformylase,
• 5-phosphoribosyl-5-amino-4-imidazolecarboxamide formyltransferase,
• AICAR formyltransferase,
• AICAR transformylase,
• aminoimidazolecarboxamide ribonucleotide transformylase, and
• transformylase,
• bifunctional purine biosynthesis protein PURH,
• ATIC.

Structural studies

As of late 2007, 11 structures have been solved for this class of enzymes, with PDB accession codes 1G8M, 1M9N, 1OZ0, 1P4R, 1PKX, 1PL0, 1THZ, 2B1G, 2B1I, 2IU0, and 2IU3.