EC Number   |
Protein Variants |
Reference |
|---|
   4.3.1.B2 | K196A/D359A |
2300fold decrease in kcat/Km of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: L-glutamine), 4fold decrease in kcat/Km of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 1fold decrease in kcat/Km of L-glutamine |
726941 |
| 4.3.1.B2 | K19S |
mutation in subunit HisF. The ammonia-dependent reactions of isolated subunit HisF_K19S is similarly efficient as that of wild-type HisF. The efficiencies of the glutamine-dependent reactions of the tHisHtHisF_K19S complex are significantly impaired |
748148 |
| 4.3.1.B2 | K258A |
ratio of glutamine turnover to N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate turnover is 43:1 (wild-type ratio is 1:1), 2600fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 385fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 1055fold decrease in kcat/Km of L-glutamine |
726939 |
| 4.3.1.B2 | K258R |
ratio of glutamine turnover to N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate turnover is 3:1 (wild-type ratio is 1:1), 20fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 125fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 45fold decrease in kcat/Km of L-glutamine |
726939 |
| 4.3.1.B2 | K360R |
ratio of glutamine turnover to N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate turnover is 1:1 (identical to wild-type ratio), 1090fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 3.5fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 6.4fold decrease in kcat/Km of L-glutamine |
726939 |
| 4.3.1.B2 | more |
eight conserved amino acids at the putative active site of subunit HisF are exchanged by site-directed mutagenesis, and the purified variants are investigated by steady state kinetics. Aspartate 11 appears to be essential for the synthase activity both in vitro and in vivo, and aspartate 130 can be partially replaced only by glutamate |
-, 748148 |
| 4.3.1.B2 | N103A |
mutation in subunit HisF. Catalytic efficiencies kcat/Km of both isolated and complexed mutant subunit HisF is not significantly different from wild-type HisF |
748148 |
| 4.3.1.B2 | N13A |
130fold decrease in kcat/Km of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: L-glutamine), 3fold decrease in kcat/Km of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 350fold decrease in kcat/Km of L-glutamine |
726941 |
| 4.3.1.B2 | Q123R |
IGP synthases formed with Q123R mutant HisF subunit has no measurable activity with glutamine in vitro |
727736 |
| 4.3.1.B2 | Q397A |
7.5fold decrease in kcat/Km of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: L-glutamine), 1fold decrease in kcat/Km of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 18fold decrease in kcat/Km of L-glutamine |
726941 |
