EC Number |
Natural Substrates |
---|
4.3.1.B2 | L-glutamine + N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate |
- |
4.3.1.B2 | N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate + L-glutamine |
for the IGP synthase holoenzyme L-glutamine is a more efficient substrate relative to ammonium ion by a factor of 1000. The HisF subunit alone does not ulilize L-glutamine. It supports an ammonia-dependent reaction with a turnover number similar to that of the holoenzyme with glutamine |
4.3.1.B2 | L-glutamine + N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate |
the enzyme catalyzes a step in the histidine biosynthetic pathway located at the branch point to de novo purine biosynthesis |
4.3.1.B2 | L-glutamine + N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate |
the imidazole glycerol phosphate synthase catalyzes formation of the imidazole ring in histidine biosynthesis |