Protein Variants | Comment | Organism |
---|---|---|
D576A | Km-value for ATP is 37.8fold higher than wild-type value, KM-value for ubiquitin is 36fold higher than wild-type value. kcat for ubiquitin adenylate formation is 250fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 28.3fold lower than wild-type value | Homo sapiens |
D576A | mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation | Homo sapiens |
D576E | Km-value for ATP is 4fold higher than wild-type value, KM-value for ubiquitin is 1.4fold higher than wild-type value. kcat for ubiquitin adenylate formation is 1200fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 34fold lower than wild-type value | Homo sapiens |
D576E | mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation | Homo sapiens |
D576N | Km-value for ATP is 5.2fold higher than wild-type value, KM-value for ubiquitin is 5fold higher than wild-type value. kcat for ubiquitin adenylate formation is 545fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 155fold lower than wild-type value | Homo sapiens |
D576N | mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation | Homo sapiens |
K528A | Km-value for ATP is 1.6fold higher than wild-type value, KM-value for ubiquitin is 2.9fold higher than wild-type value. kcat for ubiquitin adenylate formation is 400fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 309fold lower than wild-type value | Homo sapiens |
K528A | mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation | Homo sapiens |
additional information | only full-length GSTHsUba1a is catalytically active | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.000073 | - |
ubiquitin carrier protein E2 | mutant enzyme D576N | Homo sapiens | |
0.000089 | - |
ubiquitin carrier protein E2 | mutant enzyme K528A | Homo sapiens | |
0.000111 | - |
ubiquitin carrier protein E2 | wild-type enzyme | Homo sapiens | |
0.000122 | - |
ubiquitin carrier protein E2 | mutant enzyme D576E | Homo sapiens | |
0.000135 | - |
ubiquitin carrier protein E2 | mutant enzyme D576A | Homo sapiens | |
0.0008 | - |
ubiquitin | wild-type enzyme | Homo sapiens | |
0.0011 | - |
ubiquitin | mutant enzyme D576E | Homo sapiens | |
0.0011 | - |
ubiquitin | mutant D576E, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.0023 | - |
ubiquitin | mutant enzyme K528A | Homo sapiens | |
0.0023 | - |
ubiquitin | mutant K528A, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.004 | - |
ubiquitin | mutant enzyme D576N | Homo sapiens | |
0.004 | - |
ubiquitin | mutant D576N, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.0055 | - |
ATP | wild-type enzyme | Homo sapiens | |
0.0055 | - |
ATP | wild-type, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.008 | - |
ubiquitin | wild-type, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.022 | - |
ATP | mutant enzyme D576E | Homo sapiens | |
0.022 | - |
ATP | mutant D576E, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.029 | - |
ubiquitin | mutant enzyme D576A | Homo sapiens | |
0.029 | - |
ATP | mutant enzyme D576N | Homo sapiens | |
0.029 | - |
ubiquitin | mutant D576A, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.029 | - |
ATP | mutant D576N, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.119 | - |
ATP | mutant enzyme K528A | Homo sapiens | |
0.119 | - |
ATP | mutant K528A, pH 7.5, temperature not specified in the publication | Homo sapiens | |
0.208 | - |
ATP | mutant enzyme D576A | Homo sapiens | |
0.208 | - |
ATP | mutant D576A, pH 7.5, temperature not specified in the publication | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + ubiquitin + ubiquitin carrier protein E2 | - |
Homo sapiens | AMP + diphosphate + ubiquitin-(ubiquitin carrier protein E2) | - |
? | |
ATP + ubiquitin + [ubiquitin-activating protein Uba1a]-L-cysteine | - |
Homo sapiens | AMP + diphosphate + [ubiquitin-activating protein Uba1a]-S-ubiquitinyl-L-cysteine | - |
? | |
additional information | kinetics for Uba1a-catalyzed transthiolation of Ubc2b are used as a reporter assay for determining the Km and kcat values for the three cosubstrates of the ubiquitin-activating enzyme. The E2 transthiolation assays are more sensitive to the potential presence of trace catalytically active fragments than the single turnover end point assays used for quantitating ternary complex stoichiometry | Homo sapiens | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
HsUba1a | - |
Homo sapiens |
Uba1a | - |
Homo sapiens |
Ubiquitin-activating enzyme | - |
Homo sapiens |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.005 | - |
ATP | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576E | Homo sapiens | |
0.005 | - |
ubiquitin | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576E | Homo sapiens | |
0.005 | - |
ubiquitin carrier protein E2 | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576E | Homo sapiens | |
0.011 | - |
ATP | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576N | Homo sapiens | |
0.011 | - |
ubiquitin | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576N | Homo sapiens | |
0.011 | - |
ubiquitin carrier protein E2 | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576N | Homo sapiens | |
0.011 | - |
ATP | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme K528A | Homo sapiens | |
0.011 | - |
ubiquitin | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme K528A | Homo sapiens | |
0.011 | - |
ubiquitin carrier protein E2 | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme K528A | Homo sapiens | |
0.015 | - |
ATP | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme K528A | Homo sapiens | |
0.015 | - |
ubiquitin | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme K528A | Homo sapiens | |
0.015 | - |
ubiquitin carrier protein E2 | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme K528A | Homo sapiens | |
0.022 | - |
ATP | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576N | Homo sapiens | |
0.022 | - |
ubiquitin | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576N | Homo sapiens | |
0.022 | - |
ubiquitin carrier protein E2 | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576N | Homo sapiens | |
0.024 | - |
ATP | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576A | Homo sapiens | |
0.024 | - |
ubiquitin | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576A | Homo sapiens | |
0.024 | - |
ubiquitin carrier protein E2 | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, mutant enzyme D576A | Homo sapiens | |
0.1 | - |
ATP | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576E | Homo sapiens | |
0.1 | - |
ubiquitin | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576E | Homo sapiens | |
0.1 | - |
ubiquitin carrier protein E2 | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576E | Homo sapiens | |
0.12 | - |
ATP | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576A | Homo sapiens | |
0.12 | - |
ubiquitin | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576A | Homo sapiens | |
0.12 | - |
ubiquitin carrier protein E2 | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, mutant enzyme D576A | Homo sapiens | |
3.4 | - |
ATP | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, wild-type enzyme | Homo sapiens | |
3.4 | - |
ubiquitin | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, wild-type enzyme | Homo sapiens | |
3.4 | - |
ubiquitin carrier protein E2 | intrinsic kcat for transthiolation of ubiquitin carrier protein E2 corrected for saturating ATP, 125I-ubiquitin, and ubiquitin carrier protein E2, wild-type enzyme | Homo sapiens | |
6 | - |
ATP | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, wild-type enzyme | Homo sapiens | |
6 | - |
ubiquitin | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, wild-type enzyme | Homo sapiens | |
6 | - |
ubiquitin carrier protein E2 | above, intrinsic kcat for ubiquitin adenylate formation corrected for saturating ATP and 125I-ubiquitin, wild-type enzyme | Homo sapiens |