Any feedback?
Literature summary for 4.3.1.B2 extracted from
- Imidazole glycerol phosphate synthase from Thermotoga maritima. Quaternary structure, steady-state kinetics, and reaction mechanism of the bienzyme complex (2001), J. Biol. Chem., 276, 20387-20396 .
Cloned(Commentary)
| Cloned (Comment) | Organism |
|---|---|
| subunits HisH and HisF from Thermotoga maritima are produced in Escherichia coli | Thermotoga maritima |
Protein Variants
| Protein Variants | Comment | Organism |
|---|---|---|
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
| 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 | Thermotoga maritima |
KM Value [mM]
| KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| 0.0015 | - |
N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate | pH 8.5, 25°C | Thermotoga maritima |  |
| 0.32 | - |
L-glutamine | pH 8.5, 25°C | Thermotoga maritima | |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Thermotoga maritima | Q9X0C8 and Q9X0C6 | Q9X0C8: subunit HisH, Q9X0C6: subunit HisF | - |
| Thermotoga maritima DSM 3109 | Q9X0C8 and Q9X0C6 | Q9X0C8: subunit HisH, Q9X0C6: subunit HisF | - |
Purification (Commentary)
| Purification (Comment) | Organism |
|---|---|
| subunits HisH and HisF from Thermotoga maritima are produced in Escherichia coli and purified. Wild-type and active site mutants | Thermotoga maritima |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| L-glutamine + H2O | the enzyme constitutes a bienzyme complex of the glutaminase subunit HisH and the synthase subunit HisF. Nascent ammonia produced by HisH reacts at the active site of HisF with N'-((5'-phosphoribulosyl)formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide to yield the products imidazoleglycerol phosphate and 5-aminoimidazole-4-carboxamide ribotide. Isolated subunit HisH shows no detectable glutaminase activity but is stimulated by complex formation with subunit HisF to which either the product imidazole glycerol phosphate or a substrate analogue are bound | Thermotoga maritima | L-glutamate + NH3 | - |
? | |
| L-glutamine + H2O | the enzyme constitutes a bienzyme complex of the glutaminase subunit HisH and the synthase subunit HisF. Nascent ammonia produced by HisH reacts at the active site of HisF with N'-((5'-phosphoribulosyl)formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide to yield the products imidazoleglycerol phosphate and 5-aminoimidazole-4-carboxamide ribotide. Isolated subunit HisH shows no detectable glutaminase activity but is stimulated by complex formation with subunit HisF to which either the product imidazole glycerol phosphate or a substrate analogue are bound | Thermotoga maritima DSM 3109 | L-glutamate + NH3 | - |
? | |
| L-glutamine + N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate | the enzyme constitutes a bienzyme complex of the glutaminase subunit HisH and the synthase subunit HisF. Nascent ammonia produced by HisH reacts at the active site of HisF with N'-((5'-phosphoribulosyl)formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide to yield the products imidazole glycerol phosphate and 5-aminoimidazole-4-carboxamide ribotide. Isolated subunit HisH shows no detectable glutaminase activity but is stimulated by complex formation with subunit HisF to which either the product imidazole glycerol phosphate or a substrate analogue are bound | Thermotoga maritima | L-glutamate + D-erythro-1-(imidazol-4-yl)glycerol phosphate + 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide | - |
? | |
| L-glutamine + N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate | the enzyme constitutes a bienzyme complex of the glutaminase subunit HisH and the synthase subunit HisF. Nascent ammonia produced by HisH reacts at the active site of HisF with N'-((5'-phosphoribulosyl)formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide to yield the products imidazole glycerol phosphate and 5-aminoimidazole-4-carboxamide ribotide. Isolated subunit HisH shows no detectable glutaminase activity but is stimulated by complex formation with subunit HisF to which either the product imidazole glycerol phosphate or a substrate analogue are bound | Thermotoga maritima DSM 3109 | L-glutamate + D-erythro-1-(imidazol-4-yl)glycerol phosphate + 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide | - |
? | |
| N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate + NH3 | the enzyme constitutes a bienzyme complex of the glutaminase subunit HisH and the synthase subunit HisF. Nascent ammonia produced by HisH reacts at the active site of HisF with N'-((5'-phosphoribulosyl)formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide to yield the products imidazole glycerol phosphate and 5-aminoimidazole-4-carboxamide ribotide. Isolated subunit HisH shows no detectable glutaminase activity but is stimulated by complex formation with subunit HisF to which either the product imidazole glycerol phosphate or a substrate analogue are bound | Thermotoga maritima | D-erythro-1-(imidazol-4-yl)glycerol phosphate + 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide | - |
? | |
| N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-phosphate + NH3 | the enzyme constitutes a bienzyme complex of the glutaminase subunit HisH and the synthase subunit HisF. Nascent ammonia produced by HisH reacts at the active site of HisF with N'-((5'-phosphoribulosyl)formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide to yield the products imidazole glycerol phosphate and 5-aminoimidazole-4-carboxamide ribotide. Isolated subunit HisH shows no detectable glutaminase activity but is stimulated by complex formation with subunit HisF to which either the product imidazole glycerol phosphate or a substrate analogue are bound | Thermotoga maritima DSM 3109 | D-erythro-1-(imidazol-4-yl)glycerol phosphate + 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide | - |
? | |
Temperature Optimum [°C]
| Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
|---|---|---|---|
| 25 | - |
assay at | Thermotoga maritima |
Turnover Number [1/s]
| Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| 0.4 | - |
L-glutamine | pH 8.5, 25°C | Thermotoga maritima | |
| 0.8 | - |
N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate | pH 8.5, 25°C | Thermotoga maritima | |
pH Optimum
| pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
|---|---|---|---|
| 8.5 | - |
assay at | Thermotoga maritima |
General Information
| General Information | Comment | Organism |
|---|---|---|
| metabolism | the enzyme links histidine and de novo purine biosynthesis | Thermotoga maritima |
kcat/KM [mM/s]
| kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| 0.0006 | - |
N1-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamido-1-beta-D-ribofuranosyl 5'-monophosphate | pH 8.5, 25°C | Thermotoga maritima | |
| 1.4 | - |
L-glutamine | pH 8.5, 25°C | Thermotoga maritima | |
Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.
Release 2023.1 (January 2023)
Legal
Curated at
Member of
