amidophosphoribosyltransferase; ATase; glutamine phosphoribosylpyrophosphate amidotransferase; GPAT (PPAT, GPAT)

Function

• purine metabolism; IMP biosynthesis via de novo pathway
• catalyzes the first step in purine biosynthesis, transfer of the amino group of glutamine to PRPP to form 5-phosphoribosylamine
• N1-(5-phospho-D-ribosyl)glycinamide from 5-phospho-alpha-D-ribose 1-diphosphate: step 1/2

5-phospho-beta-D-ribosylamine + diphosphate + L-glutamate = L-glutamine + 5-phospho-alpha-D-ribose 1-diphosphate + H2O

Cofactor:

• binds 1 Mg+2 per subunit (putative)
• binds 1 4Fe-4S cluster per subunit (putative)

Structure

• homotetramer
• in the C-terminal section; belongs to the purine/pyrimidine phosphoribosyltransferase family
• contains 1 glutamine amidotransferase type-2 domain

Expression

ubiquitously expressed

More general terms

• phosphoribosyltransferase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5471
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5471
• OMIM: https://mirror.omim.org/entry/172450
• UniProt: http://www.uniprot.org/uniprot/Q06203.html