Peng Zhenying, Zheng Ling, Tian Haiying, Wang Jianguo, Liu Wenwen, Meng Jingjing, Zhang Jialei, Li Xinguo, Wan Shubo
Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Science, Jinan, 250100, China.
College of Life Science, Shandong Normal University, Jinan, 250014, China.
Heliyon. 2023 Jan 17;9(1):e12878. doi: 10.1016/j.heliyon.2023.e12878. eCollection 2023 Jan.
Triacylglycerols is the major storage lipid in most crop seeds. As the key enzyme catalyzing the final step of triacylglycerols biosynthesis, the activity of diacylglycerol acyltransferases directly related to oil content. It has been shown that certain amino acids are very important for enzyme activity, one amino acid variation will greatly change the enzyme activity. In this study, we identified three amino acid point mutations that affect the diacylglycerol acyltransferase 2 enzyme activity, T107M, K251R and L316P. According to the three amino acid variations, three single-nucleotide-mutant sequences of were constructed and transformed into yeast strain H1246 for function verification. Results showed that T107M and K251R could change the fatty acid content and composition of the transformed yeast strains, whereas L316P led to the loss of enzyme activity. By analyzing the 2D and 3D structures of the three variants, we found that the changes of spatial structure of T107M, K251R and L316P caused the changes of the enzyme activity. Our study could provide a theoretical basis for changing the enzyme activity of DGAT by genetic engineering, and provide a new idea for increasing the oil content of the crops.
三酰甘油是大多数作物种子中的主要储存脂质。作为催化三酰甘油生物合成最后一步的关键酶，二酰甘油酰基转移酶的活性直接与油含量相关。研究表明，某些氨基酸对酶活性非常重要，一个氨基酸变异会极大地改变酶活性。在本研究中，我们鉴定出三个影响二酰甘油酰基转移酶2酶活性的氨基酸点突变，即T107M、K251R和L316P。根据这三个氨基酸变异，构建了三个单核苷酸突变序列，并将其转化到酵母菌株H1246中进行功能验证。结果表明，T107M和K251R可改变转化酵母菌株的脂肪酸含量和组成，而L316P导致酶活性丧失。通过分析这三个变体的二维和三维结构，我们发现T107M、K251R和L316P的空间结构变化导致了酶活性的改变。我们的研究可为通过基因工程改变DGAT的酶活性提供理论依据，并为提高作物油含量提供新思路。
