In silico structure prediction and molecular docking studies of the DGAT1_2 protein from Elaeis guineensis with Oleoyl-CoA

Abstract

Diacylglycerol acyltransferase (DGAT) is a key enzyme that catalyses the last step of TAG biosynthesis, modulating lipid accumulation in plants. Parallel to growing demands for vegetable oils, Elaeis guineensis DGAT Type 1 (EgDGAT1) overexpression has been reported to improve fatty acid content, which could possibly serve as a target to enhance palm oil yield. As the EgDGAT1_2 isoform has been functionally characterised in a previous study, EgDGAT1_2 protein modelling and molecular docking were performed in this study to predict the interacting residues with oleoyl-CoA. In the absence of x-ray crystal structures, there is a need to unravel the three-dimensional (3D) structural conformations to study the binding mechanisms of EgDGAT1_2. Physical and chemical properties of EgDGAT1_2 were computed, followed by 3D structure prediction using the I-TASSER server. The model was validated using the ProSA web server, ERRAT program and PROCHECK server. The molecular docking analysis of EgDGAT1_2 with oleoyl-CoA during both blind docking and specific site docking showed favourable binding energies of -8.1 kcal/mol and -8.2 kcal/mol, respectively, and several residues were identified as potential interacting residues. Information from this study can be exploited for the molecular engineering of the native DGAT enzyme to enhance palm oil composition and yield further.