Crystallization (Comment) | Organism |
---|---|
purified recombinant wild-type and mutant enzymes, free or bound to C8 and C12, respectively, X-ray diffraction structure determination and analysis at 1.8-2.4 A resolution | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
H298E | site-directed mutagenesis, the mutant is decarboxylation deficient, residual decarboxylase activity in the range of pH 6.08.0, crystal structure determination with the mutant enzyme free or bound to C12, comparison to the wild-type enzyme structure | Escherichia coli |
H298Q | site-directed mutagenesis, the mutant is completely decarboxylation deficient, crystal structure determination with the mutant enzyme free or bound to C12, comparison to the wild-type enzyme structure | Escherichia coli |
K328A | site-directed mutagenesis, the mutant is completely decarboxylation deficient, crystal structure determination with the mutant enzyme free or bound to C12, comparison to the wild-type enzyme structure | Escherichia coli |
K328E | site-directed mutagenesis, the mutant is almost completely decarboxylation deficient | Escherichia coli |
K328F | site-directed mutagenesis, the mutant is completely decarboxylation deficient | Escherichia coli |
K328H | site-directed mutagenesis, the mutant is completely decarboxylation deficient | Escherichia coli |
K328I | site-directed mutagenesis, the mutant is almost completely decarboxylation deficient | Escherichia coli |
K328R | site-directed mutagenesis, the mutant is almost completely decarboxylation deficient, crystal structure determination with the free mutant enzyme, comparison to the wild-type enzyme structure | Escherichia coli |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
an acyl-[acyl-carrier protein] + a malonyl-[acyl-carrier protein] = a 3-oxoacyl-[acyl-carrier protein] + CO2 + an [acyl-carrier protein] | beta-ketoacyl-acyl-carrier protein synthase enzyme joins short carbon units to construct fatty acyl chains by a three-step Claisen condensation reaction, the reaction starts with a trans thioesterification of the acyl primer substrate from ACP to the enzyme, subsequently, the donor substrate malonyl-ACP is decarboxylated to form a carbanion intermediate, which in the third step attacks C1 of the primer substrate giving rise to an elongated acyl chain, H298 serves as a catalytic base in the decarboxylation step, the enzyme possesses a Cys-His-His catalytic triad, Lys328 has a dual role in catalysis: its charge influences acyl transfer to the active site Cys, and the steric restraint imposed on H333, as an obligate hydrogen bond donor at Ne, is of critical importance for decarboxylation activity, active sites of the wild-type KAS I, its H298 mutants, and their acyl complexes, overview | Escherichia coli |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
transfer of [3H]myristate from ACP to wild-type and Lys328 mutant KAS I | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
Malonyl-CoA | decarboxylation reaction | Escherichia coli | Acetyl-CoA + CO2 | - |
? | |
additional information | enzyme active site structure of wild-type and mutants with or without bound C12 or C8, overview | Escherichia coli | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | analysis of wild-type and mutant active sites with bound substrates at different pH, overview | Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
beta-ketoacyl-ACP synthase I | - |
Escherichia coli |
Cys-His-His-type beta-ketoacyl-acyl carrier protein synthase | - |
Escherichia coli |
KAS I | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
22 | - |
assay at room temperature | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.8 | - |
decarboxylation assay at, inactive at pH 4.0-5.0 | Escherichia coli |