Diacylglycerol acyltransferase (DGAT) catalyses the acylation of the sn-3 hydroxy group of sn-1,2-diacylglycerol using acyl-CoA. The gene encoding DGAT from Arabidopsis thaliana has been cloned and the function of the enzyme proved by expression of the coding sequence using a bacculovirus expression system in insect cell cultures. The expressed protein catalysed the synthesis of [14C]triacylglycerol from [14C]diacylglycerol and oleoyl-CoA. The heterologously expressed DGAT activity was found mostly associated with the 100000g pellet. The optimum activity was achieved at a neutral pH, in the presence of Mg2+, and at an optimum oleoyl-CoA concentration of 20 μM. The DGAT used the substrates palmitoyl-CoA and oleoyl-CoA equally effectively. In these experiments, the inclusion of recombinant acyl-CoA binding protein had a relatively small effect upon DGAT activity.
- acyl-CoA-binding protein
- TAG, triacylglycerol
- DGAT, diacylglycerol acyltransferase
- ACBP, acyl-CoA-binding protein
- DAG, diacylglycerol
- © 2000 Biochemical Society