嗜水气单胞菌J-1株丝氨酸蛋白酶基因克隆与序列分析

Cloning and sequence analysis of an extracellular serine-protease gene of Aeromonas hydrophila J-1

根据已发表的气单胞菌胞外蛋白酶基因核苷酸序列,设计和合成了一对引物,以嗜水气单胞菌AhJ-1的基因组DNA为模板,通过PCR技术,扩增到约900bp的丝氨酸蛋白酶基因片段,并克隆到质粒载体pGEM-T中进行测序和分析,结果表明扩增的丝氨酸蛋白酶基因片段与已发表的嗜水气单胞菌丝氨酸蛋白酶Ahe2的同源性有87％,扩增片段编码343个氮基酸,推测的分子量为35700,计算机软件分析表明编码的氨基酸有较高的抗原性,可作为核酸疫苗的侯选基因片段。

A pair of primers were designed according to the nucleotide sequences of the protease gene of Aeromonas species reported. With the specific primers, one target fragment about 900bp was amplified from Aeromonas hydrophila strain AhJ-1 genomic DNA via PCR. The PCR products were cloned into pGEM-T vector and sequenced. The sequence was compared with the corresponding regions of the GenBank strains and analyzed by DNAstar software. The nucleotide sequence showed 87 % homology to the sequence of Ahe2 gene. The nucleotide sequence was predicted to encode a 343-aa protein with the molecular weight of 35 700 and with high antigenicity. It suggested that the sequence of serine-protease gene can be used as a candidate fragment for DNA vaccine.