In Silico Analysis of Fatty Acid Desaturase Genes and Proteins in Grasses

Abstract

Fatty acid desaturases (FADs) catalyze the introduction of a double bond into acyl chains. Two FAD groups have been identified in plants: acyl-acyl carrier proteins (ACPs) and acyl-lipid or membrane-bound FAD. The former catalyze the conversion of 18:0 to 18:1 and to date have only been identified in plants. The latter are found in eukaryotes and bacteria and are responsible for multiple desaturations. In this study, we identified 82 desaturase gene and protein sequences from 10 grass species deposited in GenBank that were analyzed using bioinformatic approaches. Subcellular localization predictions of desaturase family revealed their localization in plasma membranes, chloroplasts, endoplasmic reticula, and mitochondria. The in silico mapping showed multiple chromosomal locations in most species. Furthermore, the presence of the characteristic histidine domains, the predicted motifs, and the finding of transmembrane regions strongly support the protein functionality. The identification of putative regulatory sites in the promotor and the expression profiles revealed the wide range of pathways in which fatty acid desaturases are involved. This study is an updated survey on desaturases of grasses that provides a comprehensive insight into diversity and evolution. This characterization is a necessary first step before considering these genes as candidates for new biotechnological approaches.

Overexpression of △12, △15-Desaturases for Enhanced Lipids Synthesis in Yarrowia lipolytica

“…Overexpression of this particular desaturase led to the enrichment of intracellular monounsaturated fatty acids and lipid accumulation (Qiao et al, 2015). Fatty acid desaturases, which are membrane-bound proteins, catalyze the introduction of a double bond into fatty-acid hydrocarbon chains to produce unsaturated and polyunsaturated fatty acids (PUFA) (Bai et al, 2016;Díaz et al, 2018). The fatty acid synthetic pathway includes a variety of desaturases, which are specific to the location, number, and stereochemistry of double bonds present in the fatty acids (Fickers et al, 2003).…”

Identification, Evolution, Expression, and Docking Studies of Fatty Acid Desaturase Genes in Wheat (Triticum aestivum L.)

“…The identified His-boxes in the FAB2 subfamily are related to their active sites [7]. All members of the FAD subfamily contain three His-boxes except TaFAD2.4 which had two His-Boxes and also found in a separate clade from the other TaFAD2 in the phylogenetic tree.…”

“…All members of the FAD subfamily contain three His-boxes except TaFAD2.4 which had two His-Boxes and also found in a separate clade from the other TaFAD2 in the phylogenetic tree. The third His-box was located in the carboxy-terminus of TaFAD proteins and its consensus sequence was H/QX 2 HH which is similar to FAD protein sequences in various plants [7]. The number of residues between the first and second Hisboxes varied between different members of the TaFAD subfamily (Additional file 1: Table S5).…”

“…For instance, the amino acid length between His-box 2 and His-box 3 was 111 or 171 in TaFAD2. [1][2][3][4][5][6][7][8][9][10][11]156 in TaFAD6.1-2, 162 in TaFAD3.1-6, 163 in TaFAD7.1-3 and TaFAD8.1-3, 173 in TaSLD1-3, and 127 in TaDES1-3. The exception was the TaFAD4 cluster, in which this length was only 25 amino acids.…”

“…Desaturation processes occur through two different pathways in the chloroplast and the ER [6]. In the chloroplast and ER, double bond formation requires NADPH/ferredoxin and NADH/cytochrome b 5 systems as the electron donors, respectively [7]. On the other hand, the quality of edible oils depends on the unsaturated fatty acids content [8].…”