Protein Variants | Comment | Organism |
---|---|---|
D362A | mutation in alpha subunit, 2fold increase in turnover number for NH4+, 5.4fold decrease in KM-value for NH4+, 1.7fold increase in turnover number for Gln, 1.7fold increase in KM-value for Gln | Escherichia coli |
D362A/betaR265A | mutation S362A in alpha-subunit, mutation R265A in beta-subunit,3fold increase in turnover number for NH4+, 2.2fold decrease in KM-value for NH4+, 1.2fold decrease in turnover number for Gln, 71fold increase in KM-value for Gln | Escherichia coli |
P360A/H361A | mutation in beta-subunit, turnover number for NH4+ is nearly identical to wild-type value, 1.6fold increase in turnover number for Gln, 3.2fold increase in KM-value for Gln | Escherichia coli |
P360A/H361A/R265A | mutations P360A and H361A in alpha-subunit, mutation R265A in beta-subunit, mutant enzyme is unable to utilize glutamine for the synthesis of carbamoyl phosphate1.3fold increase in turnover number for NH4+, 11.8fold decrease in KM-value for NH4+ | Escherichia coli |
Q262A/R265A | mutation in beta-subunit 1.9fold increase in turnover number for NH4+, 5fold decrease in KM-value for NH4+, 1.4fold decrease in turnover number for Gln, 43fold increase in KM-value for Gln | Escherichia coli |
Q262A/R265A/N266A | mutation in beta-subunit, 1.6fold decrease in turnover number for Gln, 13.5fold increase in KM-value for Gln | Escherichia coli |
R265A | mutation in beta-subunit, 1.3fold increase in turnover number for NH4+, 5fold decrease in KM-value for NH4+, 1.3fold decrease in turnover number for Gln, 69fold increase in KM-value for Gln | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.11 | - |
L-Gln | pH 7.6, wild-type enzyme | Escherichia coli | |
0.19 | - |
L-Gln | pH 7.6, mutant alphaD362A | Escherichia coli | |
0.36 | - |
L-Gln | pH 7.6, mutant alphaP360A/alphaH361A | Escherichia coli | |
4.7 | - |
L-Gln | pH 7.6, mutant betaQ262A/betaR265A | Escherichia coli | |
7.6 | - |
L-Gln | pH 7.6, mutant betaR265A | Escherichia coli | |
7.8 | - |
L-Gln | pH 7.6, mutant alphaD362A/betaR265A | Escherichia coli | |
12 | - |
NH4+ | pH 7.6, mutant alphaP360A/alphaH361A/betaR265A | Escherichia coli | |
14.9 | - |
L-Gln | pH 7.6, mutant betaQ262A/betaR265A/betaN266A | Escherichia coli | |
24 | - |
NH4+ | pH 7.6, mutant alphaD362A | Escherichia coli | |
26 | - |
NH4+ | pH 7.6, mutant betaQ262A/betaR265A | Escherichia coli | |
26 | - |
NH4+ | pH 7.6, mutant betaR265A | Escherichia coli | |
59 | - |
NH4+ | pH 7.6, mutant alphaD362A/betaR265A | Escherichia coli | |
130 | - |
NH4+ | pH 7.6, wild-type enzyme | Escherichia coli |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ATP + L-Gln + HCO3- | carbamoyl phosphate synthetase contains an internal molecular tunnel, which has been proposed to facilitate the translocation of reaction intermediates from one active site to another. Ammonia, the product from the hydrolysis of glutamine in the small subunit, is apparently transported to the next active site in the large subunit of CPS over a distance of about 45 Å. The ammonia tunnel that connects these two active sites provides a direct path for the guided diffusion of ammonia and protection from protonation | Escherichia coli | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
2 ATP + NH4+ + HCO3- | the enzyme is able to utilize external NH4+ as an alternative nitrogen source when glutamine is absent | Escherichia coli | 2 ADP + phosphate + carbamoyl phosphate | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.005 | - |
L-Gln | pH 7.6, mutant alphaP360A/alphaH361A/betaR265A | Escherichia coli | |
0.88 | - |
L-Gln | pH 7.6, mutant betaQ262A/betaR265A/betaN266A | Escherichia coli | |
1 | - |
L-Gln | pH 7.6, mutant betaQ262A/betaR265A | Escherichia coli | |
1.1 | - |
L-Gln | pH 7.6, mutant betaR265A | Escherichia coli | |
1.2 | - |
L-Gln | pH 7.6, mutant alphaD362A/betaR265A | Escherichia coli | |
1.4 | - |
L-Gln | pH 7.6, wild-type enzyme | Escherichia coli | |
1.9 | - |
NH4+ | pH 7.6, wild-type enzyme | Escherichia coli | |
2 | - |
NH4+ | pH 7.6, mutant alphaP360A/alphaH361A | Escherichia coli | |
2.3 | - |
L-Gln | pH 7.6, mutant alphaP360A/alphaH361A | Escherichia coli | |
2.4 | - |
L-Gln | pH 7.6, mutant alphaD362A | Escherichia coli | |
2.5 | - |
NH4+ | pH 7.6, mutant alphaP360A/alphaH361A/betaR265A | Escherichia coli | |
2.5 | - |
NH4+ | pH 7.6, mutant betaR265A | Escherichia coli | |
3.6 | - |
NH4+ | pH 7.6, mutant betaQ262A/betaR265A | Escherichia coli | |
3.8 | - |
NH4+ | pH 7.6, mutant alphaD362A | Escherichia coli | |
5.8 | - |
NH4+ | pH 7.6, mutant alphaD362A/betaR265A | Escherichia coli |