马蔺DFR基因的克隆及生物信息学特征分析

Cloning and Bioinformatic Analysis of DFR Gene FromIris lactea Pall.var.chinensis(Fisch.)Koidz

以马蔺花瓣为试材,通过转录组测序,应用PCR技术克隆马蔺花青素生物合成关键酶二羟黄酮醇-4-还原酶(dihydvroflavonol-4-reductase,DFR)基因并获得其生物信息学特征。结果表明:马蔺DFR基因全长1 427bp,共编码357个氨基酸(该基因命名为IlDFR,GenBank登录号为KY907171)。该基因在氨基酸水平上与多种植物的DFR具有较高的同源性,在系统进化上与同属的荷兰鸢尾(Iris hollandica)的DFR亲缘关系较近;预测其蛋白质相对分子质量为39.99kDa,等电点为5.89,主要由α-螺旋和β-折叠构成,定位于细胞质,属于酸性亲水不含信号肽的不稳定类蛋白质。马蔺IlDFR有一段氨基酸序列‘VTGASGYVGSWLVMKLLRDGY’与大部分物种的DFR特有相对保守的NADPH结合域非常相似,只有4个氨基酸残基有所差异。

Iris lactea Pall.var.chinensis（Fisch.）Koidz petals were used as material for transcriptome sequencing.According to the annotation data,a key gene encodes dihydvroflavonol-4-reductase（DFR）in its anthocyanin biosynthesis was cloned by using PCR amplification and was charactered using bioinformatic analysis.The full-length of DFR gene of I.lactea var.chinensis consisted of 1 427 bp encoding aprotein with 357 amino acid residues（designated as IlDFR,accession No.KY907171）.Based on the comparison of the deduced amino acid sequence,IlDFR shared high identity with other plant DFRs,and had high homology with congeneric Iris hollandica DFR.IlDFR had a predicted molecular mass of 39.99 kDa and an isoelectric point of 5.89.It mainly composed ofα-helixes andβ-sheets,and was considered as an acidic,hydrophilic,no signal peptide and labile protein that located in the cytoplasm.IlDFR had a ‘VTGASGYVGSWLVMKLLRDGY＇amino acid sequence that was similar to the NADPH binding domain which was a typical conserved sequence in most of other plant DFRs,but differenced in 4 amino acid residues.