摘要
根据樟叶越桔(Vaccinium dunalianum)叶芽转录组测序获得的熊果苷合成酶基因Vd AS1部分EST序列设计引物,结合RACE-PCR技术获得Vd AS1基因全长1 577 bp c DNA序列。其完整的开放阅读框推测编码由475个氨基酸残基组成的Vd AS1蛋白,理论相对分子量为52.22 k D,等电点p I=5.74,负电荷残基(Asp+Glu)总数为53个,正电荷残基(Arg+Lys)总数为45个,不稳定系数为37.93,属稳定性蛋白质。生物信息学分析表明Vd AS1与枸杞的糖基转移酶相似率高达74%,其二级结构主要构件为α-螺旋和随机卷曲,不存在跨膜区,属于亲水性蛋白质,并结合信号肽预测结果推测Vd AS1直接锚定在细胞基质中行使功能。该研究为后期Vd AS1的异源表达和功能研究奠定了基础。
Arbutin was widely used in cosmetics as a whitening agent because of blocking the synthesis of melanin as the inhibitor of tyrosinase. Arbutin synthase （AS） as one member of UDP glycosyltransferases （UGTs） which belongs to the glycosyltransferase （GTs） family is a rate-limiting enzyme in arbutin synthesis from hydroquinone. To reveal the biological function and provide scientific basis of application on plant genetic engineering for Vaccinium dunalianum arbutin synthase （VdAS）, a gene VclAS1 encoding VdAS1 was isolated by RT-PCR combined with RACE-PCR from V. dunalianum. The full-length eDNA clone comprised 1 577 nucleotides consisting of a 17-nncleo- tide 5＇-untranslated region, an open reading frame of 1428 nucleotides, and a 132-nucleotide 3＇-untranslated region. The open reading frame encoded a putative VdAS1 comprising 475 amino acid residues with molecular weight of 52. 22 kD. and isoelectrie point of 5.74. The total numbers of negative charged residues （Asp＋Glu） and positive charged residues （Arg＋Lys） in VdAS1 were 53 and 45, respectively. VdAS1 shares 74% similarity with UGT in wolfberry （Lyciurn barbarum）. It was predictive VdAS1 had no signal peptide and transmembrane structure. The main parts of predicted secondary structures of VdAS1 were a-helices and random coils. The study results established the foundation for the heterologous expression and functional analysis of VdAS1.
出处
《植物分类与资源学报》
CAS
CSCD
北大核心
2015年第1期71-77,共7页
Plant Diversity
基金
国家自然科学基金地区科学基金项目(21462040
31460076)
云南省优势特色重点学科生物学一级学科建设项目(50097505)
