4.3.1.B2	C124R	IGP synthases formed with Q123R mutant HisF subunit has no measurable activity with glutamine in vitro	727736	
4.3.1.B2	C9A	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	D11N	mutation in subunit HisF. Catalytic efficiency kcat/Km for N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate is decreased by approximately 5 orders of magnitude	748148	
4.3.1.B2	D130N	the kcat value is reduced by a factor of about 400-500, and the Km for N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate is increased almost 20fold. Catalytic efficiency kcat/Km for N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate is decreased by approximately 5 orders of magnitude	-, 748148	
4.3.1.B2	D176N	mutation in subunit HisF. The variant tHisF_D176N shows a 40-50 fold decrease in kcat, both in isolated form and in complex with tHisH	-, 748148	
4.3.1.B2	D183N	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	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+), 7.5fold decrease in kcat/Km of L-glutamine	726941	
4.3.1.B2	D51N	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	E46G	IGP synthases formed with E46G mutant HisF subunit shows 2800fold reduction in the kcat/Km ratio for glutamine	727736	
4.3.1.B2	K196A	0.43fold 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+), 3fold decrease in kcat/Km of L-glutamine	726941	
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	additional information	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	
4.3.1.B2	R239A	ratio of glutamine turnover to N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate turnover is 122:1 (wild-type ratio is 1:1), 860fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 5.4fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 3450fold decrease in kcat/Km of L-glutamine	726939	
4.3.1.B2	R239H	ratio of glutamine turnover to N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate turnover is 154:1 (wild-type ratio is 1:1), 2400fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 5.2fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 1360fold decrease in kcat/Km of L-glutamine	726939	
4.3.1.B2	R239K	ratio of glutamine turnover to N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate turnover is 40:1 (wild-type ratio is 1:1), 218fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 3.9fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 540fold decrease in kcat/Km of L-glutamine	726939	
4.3.1.B2	R360A	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), 9.2fold decrease in kcat/KM of N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate L-glutamine), 1.4fold decrease in kcat/Km N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate (cosubstrate: NH4+), 15fold decrease in kcat/Km of L-glutamine	726939	
4.3.1.B2	R5H	IGP synthases formed with R5H mutant HisF subunit shows 1500fold reduction in the kcat/Km ratio for glutamine	727736	
4.3.1.B2	T78M	the mutation does not impair substrate binding to the active site of HisF	728756