Figure 2.

The histidine biosynthetic pathway in Arabidopsis. Abbreviations used for enzyme names are indicated in parentheses, and the corresponding Arabidopsis gene names and AGI codes are shown in blue. Allosteric inhibition of ATP-PRT activity by L-His is indicated in red. Abbreviations used for intermediates are: PRPP (5′-phosphoribosyl-1-pyrophosphate), PRATP (N′-5′-phosphoribosyl-ATP), PRAMP (N′-5′-phosphoribosyl-AMP), ProFAR (N′-[(5′-phosphoribosyl)formimino]-5-aminoimidazole-4-carboxamide) ribonucleotide, PRFAR (N′-[(5-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamide) ribonucleotide, IGP (imidazole glycerol-phosphate), IAP (imidazole acetol-phosphate), AICAR (5′-phosphoribosyl-4-carboximide-5-aminoimidazole) and 2-OG (2-oxoglutarate). Hyperlinks to chemical structures and TAIR locus pages are provided.