毛竹β-1,3-葡聚糖酶基因的克隆及序列分析(英文)

Cloning and Sequencing Analysis of β-1,3-glucanase Gene from Moso Bamboo

β-1,3-葡聚糖酶是一种植物病程相关蛋白,在植物抵御病害中有重要作用。本研究以毛竹为实验材料,利用RACE技术,克隆毛竹β-1,3-葡聚糖酶基因的外显子序列,并在β-1,3-葡聚糖酶基因的编码区两端设计引物,以毛竹基因组DNA为模版扩增该基因的内含子序列。序列结果表明,该基因全长1693bp,包含两个外显子和一个内含子,命名为PheGLU(GenBank登录号GU238236)。该基因包含1个996bp的开放阅读框,编码332个氨基酸,相对分子质量为3.541×104Da,其等电点pI为6.389,是一个酸性蛋白且分泌到胞外;其中,该蛋白的二级结构中包含35.15%的α-螺旋,21.82%的β-转角,43.03%的延伸链和无规则卷曲等;三级结构同源建模预测显示,它与大麦β-1,3-葡聚糖酶(PDB number:1ghsA)具有80.4%的同源性;聚类分析显示,该基因序列与已报道的其它植物具有较的高氨基酸序列同源性。本研究为进一步鉴定毛竹β-1,3-葡聚糖酶基因的抗真菌病害能力奠定了基础。

β-1,3-glucanase is one kind of plant pathogenesis-related proteins,and plays an important role in plant pathogen defence.In this research,we employed moso bamboo（Phyllostachys edulis） to be as material for cloning the exon sequence of β-1,3-glucanase gene by using RACE technique,and amplified the intron fragment of β-1,3-glucanase gene from moso bamboo genomic DNA by using primers designed based on its coded region.Sequence analysis showed that the full-length sequence of β-1,3-glucanase gene was 1 693 bp,containing two exons and one intron,which named as PheGLU（GenBank Accession No.GU238236）,as well as a ORF（open reading frame） encoded 332 amino acids according to 1 693 bp,which had calculated molecular weight of 3.541×104 Da and predicted isoelectric point of 6.389,it belonged to acidic protein and secreted into the extra cellular space.The secondary structure of this protein harbored 35.15% helix,21.82% sheets and 43.03% turns,strands,random coils,etc;its crystal structure similarity to barley β-1,3-glucanase（PDB number：1ghsA） was as high as 80.4%.The clustering analysis indicated the high amino acids alignment homologies of β-1,3-glucanase with other monocot species.This study would lay a basis for identifying the antifungal ability of β-1,3-glucanase gene.