Isolation of palmitoyl-acp thioesterase gene from Chlorella sp

Abstract

Palmitoyl-ACP thioesterase (PTE) involves in the synthesis of palmitate (Cl6:0) from palmitoyl-ACP (16:0-ACP) in fatty acid biosynthesis pathway. The significant role of PTE in this pathway is the basis for the isolation of the gene from Chlorella sp. The total RNA extracted from Chlorella sp. was reverse transcribed with KPN-Tl 7 oligo­ dT primer by using M-MLV reverse transcriptase. Four heterologous forward primers designed from the conserved regions of the PTE gene were used to amplify the corresponding 3 '-end regions of the gene. PCR amplification successfully produced five putative DNA fragments with size ranging from 600 bp to 1300 bp. These five putative fragments were cloned into pGEM-T vector and the plasmids extracted from the positive recombinant clones were sent for DNA sequencing to determine their nucleotide sequences. Analysis of sequencing results by searching the GenBank database using BLAST programme revealed that there were no homology to the target PTE gene. Instead, the sequences show homology to other genes, such as eukaryotic translation elongation factor 1 alpha 1 (XP _ 001696568), aspartate aminotransferase (AAN76499), hypothetical protein (CAN76227), and SocE (AAF91388).