Inosine monophosphate synthase

Bifunctional purine biosynthesis protein PURH is a protein that in humans is encoded by the ATIC gene.^[5][6][7]

ATIC
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1P4R, 1PKX, 1PL0
Identifiers
Aliases	ATIC, AICAR, AICARFT, HEL-S-70p, IMPCHASE, PURH, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase
External IDs	OMIM: 601731; MGI: 1351352; HomoloGene: 2983; GeneCards: ATIC; OMA:ATIC - orthologs
Gene location (Human) Chr. Chromosome 2 (human)[1] Band 2q35 Start 215,311,956 bp[1] End 215,349,773 bp[1]
Gene location (Mouse) Chr. Chromosome 1 (mouse)[2] Band 1|1 C3 Start 71,596,309 bp[2] End 71,618,790 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in mucosa of transverse colon stromal cell of endometrium rectum anterior pituitary ventricular zone right adrenal cortex body of pancreas gonad ganglionic eminence left adrenal cortex Top expressed in hand epiblast condyle mandibular prominence maxillary prominence transitional epithelium of urinary bladder abdominal wall mesenteric lymph nodes primitive streak foot More reference expression data BioGPS More reference expression data
Gene ontology Molecular function transferase activity protein homodimerization activity IMP cyclohydrolase activity catalytic activity phosphoribosylaminoimidazolecarboxamide formyltransferase activity hydrolase activity cadherin binding Cellular component cytosol membrane mitochondrion extracellular exosome plasma membrane Biological process purine nucleotide biosynthetic process dihydrofolate metabolic process 'de novo' IMP biosynthetic process brainstem development ribonucleotide metabolic process cerebellum development nucleoside metabolic process tetrahydrofolate biosynthetic process animal organ regeneration response to inorganic substance cerebral cortex development purine ribonucleoside monophosphate biosynthetic process metabolism nucleobase-containing compound metabolic process cellular response to interleukin-7 Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 471 108147 Ensembl ENSG00000138363 ENSMUSG00000026192 UniProt P31939 Q9CWJ9 RefSeq (mRNA) NM_004044 NM_026195 RefSeq (protein) NP_004035 NP_080471 Location (UCSC) Chr 2: 215.31 – 215.35 Mb Chr 1: 71.6 – 71.62 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

ATIC encodes an enzyme which generates inosine monophosphate from aminoimidazole carboxamide ribonucleotide (AICA ribonucleotide).

It has two functions:

• EC 2.1.2.3 - 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase

In this step, AICA ribonucleotide is formylated, with the formyl group being transferred from the cofactor 5,10-methylenetetrahydrofolate (5,10-CH₂-THF).^[8]

AICA ribonucleotide

+ 5,10-CH₂-THF

 

 

 

 

 

 

 

N-formyl AICA ribonucleotide

+ tetrahydrofolate

 

• EC 3.5.4.10 - IMP cyclohydrolase

This enzyme forms the purine ring of inosine monophosphate by dehydration and cyclisation of N-formyl AICA ribonucleotide.^[9]

N-formyl AICA ribonucleotide

 

 

H₂O

 

 

 

inosinic acid