Subhash J Bhore1, Thye S Cha2, Kassim Amelia1, Farida H Shah3
1 Department of Molecular Biology, Melaka Institute of Biotechnology, Lot 7, Melaka International Trade Centre City, 75450 Ayer Keroh, Melaka; Department of Biotechnology, Faculty of Applied Sciences, AIMST University, Bedong Semeling Road, Bedong, 08100, Kedah, Malaysia
2 School of Bioscience and Biotechnology, Faculty of Science and Technology, National University of Malaysia (UKM), 43600 Bangi, Selangor; Department of Biological Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), 21030 Kuala Terengganu, Malaysia
3 Department of Molecular Biology, Melaka Institute of Biotechnology, Lot 7, Melaka International Trade Centre City, 75450 Ayer Keroh, Melaka; School of Bioscience and Biotechnology, Faculty of Science and Technology, National University of Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
Background: Palm oil derived from fruits (mesocarp) of African oil palm (Elaeis guineensis Jacq. Tenera) and American oil palm (E. oleifera) is important for food industry. Due to high yield, Elaeis guineensis (Tenera) is cultivated on commercial scale, though its oil contains high (~54%) level of saturated fatty acids. The rate-limiting activity of beta-ketoacyl-[ACP] synthase-II (KAS-II) is considered mainly responsible for the high (44%) level of palmitic acid (C 16:0 ) in the oil obtained from E. guineensis. Objective: The objective of this study was to annotate KAS-II cDNA isolated from American and African oil palms. Materials and Methods: The full-length E. oleifera KAS-II (EoKAS-II) cDNA clone was isolated using random method of gene isolation. Whereas, the E. guineensis KAS-II (EgTKAS-II) cDNA was isolated using reverse transcriptase polymerase chain reaction (RT-PCR) technique; and missing ends were obtained by employing 5’and 3′ RACE technique. Results: The results show that EoKAS-II and EgTKAS-II open reading frames (ORFs) are of 1689 and 1721 bp in length, respectively. Further analysis of the both EoKAS-II and EgTKAS-II predicted protein illustrates that they contains conserved domains for ‘KAS-I and II’, ‘elongating’ condensing enzymes, ‘condensing enzymes super-family’, and ‘3-oxoacyl-[ACP] synthase II’. The predicted protein sequences shows 95% similarity with each other. Consecutively, the three active sites (Cys, His, and His) were identified in both proteins. However, difference in positions of two active Histidine (His) residues was noticed. Conclusion: These insights may serve as the foundation in understanding the variable activity of KAS-II in American and African oil palms; and cDNA clones could be useful in the genetic engineering of oil palms.
Keywords: African oil palm, American oil palm, cooking oil, edible oil, Elaeis oleifera, Elaeis guineensis, fatty acids, oil palm, palm oil