Cloned (Comment) | Organism |
---|---|
isozyme BnaC.DGAT1.a, recombinant expression of wild-type and truncated mutant enzymes in Saccharomyces cerevisiae strain H1246, which is devoid of TAG biosynthesis | Brassica napus |
Protein Variants | Comment | Organism |
---|---|---|
additional information | construction of several truncated enzyme versions of isozyme BnaC.DGAT1.a, BnaDGAT161-501 and BnaDGAT181-501 exhibit higher normalized specific activity compared with the full-length enzyme. Despite the lower production level of BnaDGAT161-501 and BnaDGAT181-501, these enzyme forms are able to generate TAG amounting to about 60% of the total triacylglycerol (TAG) produced by the full-length enzyme in situ. Mutant BnaDGAT1114-501,which is devoid of the entire N-terminal domain, is about 10fold less active than the full-length enzyme. The affinity of BnaDGAT1114-501 for acyl-CoA is much lower than that of the full-length BnaDGAT1 or BnaDGAT181-501. Residues 81 to 113 are important in maintaining high activity and affinity for the acyl donor at the active site | Brassica napus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
acyl-CoA | substrate inhibition is observed at higher concentrations of acyl-CoA | Brassica napus | |
CoA | noncompetitively inhibits isozyme BnaC.DGAT1.a. The N-terminal domain of isoform BnaA.DGAT1.b can interact with acyl-CoA at a possible allosteric site, and CoA can displace the thioester | Brassica napus | |
additional information | the highly disordered segment at the enzyme's N-terminus is involved in the downregulation of DGAT1 activity, suggesting the presence of an autoinhibitory motif | Brassica napus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | isozyme BnaC.DGAT1.a exhibits positive cooperativity. The folded section of the enzyme is important to maintain high acyl-CoA affinity at the active site and activity. Kinetics of wild-type and enzyme mutants, Michaelis-Menten kinetic model | Brassica napus | |
0.00055 | - |
oleoyl-CoA | pH 7.4, 30°C, recombinant truncated enzyme mutant BnaDGAT181-501 | Brassica napus | |
0.00061 | - |
oleoyl-CoA | pH 7.4, 30°C, recombinant full-length wild-type enzyme | Brassica napus | |
0.00067 | - |
palmitoyl-CoA | pH 7.4, 30°C, recombinant truncated enzyme mutant BnaDGAT181-501 | Brassica napus | |
0.00069 | - |
palmitoyl-CoA | pH 7.4, 30°C, recombinant full-length wild-type enzyme | Brassica napus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | DGAT1 has 8 to 10 transmembrane domains | Brassica napus | 16020 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Brassica napus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
acyl-CoA + 1,2-diacyl-sn-glycerol | Brassica napus | - |
CoA + 1,2,3-triacylglycerol | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Brassica napus | K9LL63 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
acyl-CoA + 1,2-diacyl-sn-glycerol | - |
Brassica napus | CoA + 1,2,3-triacylglycerol | - |
? | |
additional information | the acyl-CoA binding site is located at N-terminal domain of DGAT1 along amino acid residues 81 to 113 | Brassica napus | ? | - |
- |
|
oleoyl-CoA + 1,2-dioleoyl-sn-glycerol | - |
Brassica napus | CoA + 1,2,3-trioleoylglycerol | - |
? | |
palmitoyl-CoA + 1,2-dioleoyl-sn-glycerol | - |
Brassica napus | CoA + 1,2-dioleoyl-3-palmitoylglycerol | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | the BnaDGAT1 N-terminal region is required for interactions leading to the dimeric enzyme form, which may allow it to partially mediate positive cooperativity through intermolecular interaction | Brassica napus |
More | the full-length polypeptide is predominantly well folded (about 68% alpha-helices/beta-sheets), while the N-terminal domain only has about 29% alpha-helices/beta-sheets | Brassica napus |
Synonyms | Comment | Organism |
---|---|---|
BnaC.DGAT1.a | - |
Brassica napus |
BnaDGAT1 | - |
Brassica napus |
DGAT1 | - |
Brassica napus |
diacylglycerol acyltransferase 1 | - |
Brassica napus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Brassica napus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Brassica napus |
General Information | Comment | Organism |
---|---|---|
evolution | DGAT1 belongs to a family of enzymes named membrane-bound O-acyltransferases (MBOATs). The DGAT1 family is highly conserved. DGAT1 possesses a very hydrophilic N-terminal region corresponding to about the first 100 residues, which is followed by eight to ten predicted transmembrane segments | Brassica napus |
malfunction | BnaDGAT161-501 and BnaDGAT181-501 exhibit higher normalized specific activity compared with the full-length enzyme. Despite the lower production level of BnaDGAT161-501 and BnaDGAT181-501, these enzyme forms are able to generate TAG amounting to about 60% of the total triacylglycerol (TAG) produced by the full-length enzyme in situ. Mutant BnaDGAT1114-501, which is devoid of the entire N-terminal domain, is about 10fold less active than the full-length enzyme. The affinity of BnaDGAT1114-501 for acyl-CoA is much lower than that of the full-length BnaDGAT1 or BnaDGAT181-501. Residues 81 to 113 are important in maintaining high activity and affinity for the acyl donor at the active site | Brassica napus |
additional information | DGAT1 enzymes may be regulated through allosteric interactions. The self-association properties of DGAT1 enzymes are consistent with the fact that most allosteric enzymes exhibit quaternary structure, identification of CoA/acyl-CoA binding site in the hydrophilic N-terminal domain and specific interactions involved in CoA recognition, and analysis of structure and function of the hydrophilic N-terminal domain of Brassica napus DGAT1, overview. This domain is found to have an intrinsically disordered region (IDR) and a folded section. IDRs are recognized as important regions in proteins due to their roles in cellular signaling and regulation. The highly disordered segment is involved in the downregulation of DGAT1 activity, suggesting the presence of an autoinhibitory motif. Isozyme BnaC.DGAT1.a also exhibits positive cooperativity. The involvement of the N-terminal domain in self-association may mediate positive cooperativity. The folded section of the enzyme is important to maintain high acyl-CoA affinity at the active site and activity. The BnaDGAT1 N-terminal domain is not necessary for catalysis but contributes to modulating activity. Residues 81 to 113 are important in maintaining high activity and affinity for the acyl donor at the active site. The BnaDGAT1 N-terminal region is required for interactions leading to the dimeric enzyme form, which may allow it to partially mediate positive cooperativity through intermolecular interaction. The BnaDGAT1 N-terminal Domain is structurally flexible. The allosteric site also is needed for acyl-CoA-mediated homotropic allosteric activation | Brassica napus |
physiological function | diacylglycerol acyltransferase 1 (DGAT1) is an integral membrane enzyme catalyzing the final and committed step in the acylcoenzyme A (CoA)-dependent biosynthesis of triacylglycerol (TAG). Proposed model for BnaDGAT1 regulation involving the hydrophilic N-terminal domain (NTD), overview | Brassica napus |