Subsystem: Histidine Biosynthesis
This subsystem's description is:
PRPP, from the pentose phosphate pathway, and ATP are the substrates of the first reaction catalyzed by ATP phosphoribosyltransferase (HisA). This is a highly regulated phosphotransferase. HisAa, is an ATP phosphoribosyltransferase catalytic subunit, and HisAb and HisAb2 are ATP phosphoribosyltransferase regulatory subunits that may assist in the formation of the first product of the pathway, phosphoribosyl-ATP. The next three steps in the pathway include phosphoribosyl-ATP pyrophosphatase, phosphoribosyl-AMP cyclohydrolase and phosphoribosylformimino-5-aminoimidazole carboxamide ribotide isomerase (HisB, HisC, and HisD, respectively). Imidazole glycerol phosphate synthase has a cyclase subunit (HisEa) and an amidotransferase subunit (His Eb). These steps are followed by ones catalyzed by imidazoleglycerol-phosphate dehydratase (HisF), and histidinol-phosphate aminotransferase (HisG). Histidinol-phosphatase (HisH), the next step in the pathway, may have an alternative form (HisH2). The final step of the histidine pathway, histidinol dehydrogenase (HisI) produces L-Histidine.
For more information, please check out the description and the additional notes tabs, below
|Diagram||Functional Roles||Subsystem Spreadsheet||Description||Additional Notes||Scenarios|
Oops! We thought there was a diagram here, but we can't find it. Sorry