Cloned (Comment) | Organism |
---|---|
wild-type enzyme and mutants Y268F and Y294F as His6-tagged proteins in Escherichia coli | Pseudomonas sp. |
Protein Variants | Comment | Organism |
---|---|---|
E295D | site-directed mutagesis, mutant kinetics compared to the wild-type, overview | Pseudomonas sp. |
Y268F | site-directed mutagesis, mutant kinetics compared to the wild-type, overview | Pseudomonas sp. |
Y294F | site-directed mutagesis, mutant kinetics compared to the wild-type, overview | Pseudomonas sp. |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | steady-state kinetics and pH-dependence, overview | Pseudomonas sp. |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
1-aminocyclopropane-1-carboxylate + H2O | Pseudomonas sp. | - |
2-oxobutanoate + NH3 | - |
? | |
1-aminocyclopropane-1-carboxylate + H2O | Pseudomonas sp. ACP | - |
2-oxobutanoate + NH3 | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pseudomonas sp. | - |
- |
- |
Pseudomonas sp. ACP | - |
- |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
1-aminocyclopropane-1-carboxylate + H2O = 2-oxobutanoate + NH3 | reaction mechanism, detailed overview | Pseudomonas sp. |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
1-aminocyclopropane-1-carboxylate + H2O | - |
Pseudomonas sp. | 2-oxobutanoate + NH3 | - |
? | |
1-aminocyclopropane-1-carboxylate + H2O | the pyridoxal 5'-phosphate-dependent enzyme cleaves the cyclopropane ring of ACC, to give 2-oxobutyric acid and ammonia as products. The pKa of the conserved active site residue, Tyr294, is lowered by a hydrogen bonding interaction with a second conserved residue, Tyr268. This allows Tyr294 to deprotonate the incoming amino group of ACC to initiate the aldimine exchange reaction between ACC and the pyridoxal 5'-phosphate coenzyme and also likely helps to activate Tyr294 for a role as a nucleophile to attack and cleave the cyclopropane ring of the substrate. The Calpha-Cbeta bond cleavage step in the chemical mechanism is at least partially rate-limiting under kcat/Km conditions and is likely preceded in the mechanism by a partially rate-limiting step involving the conversion of a stable gem-diamine intermediate into a reactive external aldimine intermediate that is poised for cyclopropane ring cleavage | Pseudomonas sp. | 2-oxobutanoate + NH3 | - |
? | |
1-aminocyclopropane-1-carboxylate + H2O | - |
Pseudomonas sp. ACP | 2-oxobutanoate + NH3 | - |
? | |
1-aminocyclopropane-1-carboxylate + H2O | the pyridoxal 5'-phosphate-dependent enzyme cleaves the cyclopropane ring of ACC, to give 2-oxobutyric acid and ammonia as products. The pKa of the conserved active site residue, Tyr294, is lowered by a hydrogen bonding interaction with a second conserved residue, Tyr268. This allows Tyr294 to deprotonate the incoming amino group of ACC to initiate the aldimine exchange reaction between ACC and the pyridoxal 5'-phosphate coenzyme and also likely helps to activate Tyr294 for a role as a nucleophile to attack and cleave the cyclopropane ring of the substrate. The Calpha-Cbeta bond cleavage step in the chemical mechanism is at least partially rate-limiting under kcat/Km conditions and is likely preceded in the mechanism by a partially rate-limiting step involving the conversion of a stable gem-diamine intermediate into a reactive external aldimine intermediate that is poised for cyclopropane ring cleavage | Pseudomonas sp. ACP | 2-oxobutanoate + NH3 | - |
? |
Synonyms | Comment | Organism |
---|---|---|
ACC deaminase | - |
Pseudomonas sp. |
ACCD | - |
Pseudomonas sp. |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Pseudomonas sp. |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
steady-state kinetics and pH-dependence, overview | Pseudomonas sp. |
7.5 | - |
assay at for wild-type enzyme and mutants E295D and Y294F | Pseudomonas sp. |
8.8 | - |
assay at for mutant Y268F | Pseudomonas sp. |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | dependent on | Pseudomonas sp. |