苏云金芽胞杆菌酰基高丝氨酸内酯酶基因的克隆及分析

利用pMD18-T克隆载体从苏云金芽胞杆菌菌株WB12中克隆了酰基高丝氨酸内酯酶基因(AHL-lactonase,aiiA).测序结果表明,该基因(GenBank登录号为DQ000642)由753个碱基组成,编码含有250个氨基酸残基的蛋白质.推测该蛋白质分子质量为28 ku,等电点为4.2,不含信号肽序列.利用DNAMAN软件构建同源关系树.结果表明,该蛋白与已报道具有减弱欧文氏菌胡萝卜亚种致病力的11个A iiA蛋白酶氨基酸序列总相似性为81.2%,并含有相同的氨基酸序列保守区.核苷酸序列的BLAST分析结果表明,与之同源性较高的基因均为蜡质芽孢杆菌组aiiA基因(86%-99%).

Cloning and sequence analysis of AHL-lactonase gene from Bacillus thuringiensis

A novel AHL-lactonase gene(aiiA) was cloned from Bacillus thuringiensis WB12 by PCR with pMD18-T vector and sequenced.The nucleotide sequence has been registered in GenBank with accession number DQ000642.It consists of 753 bases which encodes a polypeptide of 250 amino acids residues with a calculated molecular weight of 28 ku and an isoelectric point value of 4.2.No signal peptide was found in WB12 AiiA.On the basis of the multiple alignment of amino acid sequences of this AiiA and other 10 AiiA,which are capable of attenuating the plant pathogenicity of Erwinia carotovora var.carotovora,a homology tree was constructed using DNAMAN.The result showed that the amino acid sequences of the proteins were 81.2% identical overall and share same conserved regions.BLAST analysis of its nucleotide sequence showed 86%-99% identity with those of the aiiA genes from B.cereus group.