鸡大肠杆菌1型菌毛fimH蛋白结构基因克隆及序列测定

The Coloning and Sequcencing of fimH Gene of Type 1 Pili in Avian Escherichia coli

根据已发表的大肠杆菌1型菌毛fimH基因序列,以产1型菌毛菌株MG2(O11)、YR5(O78)、MG12(O18)基因组DNA为模板,对大肠杆菌1型菌毛fimH基因进行扩增并与国外同源菌株基因序列进行比对。结果表明:核酸同源性分别为97.8%、99.7%、97.8%,氨基酸序列的相似性分别达到98.7%、99.3%、98.0%。运用DNA-STAR软件对fimH蛋白抗原决定簇进行预测分析,发现它们的抗原决定簇基本相似,这说明fimH基因序列及氨基酸序列的变异并未对fimH蛋白的抗原结构产生明显影响。

In this study, through polymerases chain reaction, the firaH gene is amplified by PCR from the DNA template of Escherichia coli MG2（Oll）,YR5（O78） and MG12（O18）, then the PCR product is cloned and the nueleotide sequence is determined through related software analysis. It is found that nucleotide sequence of fimH gene both in avian Escherichia coli and K-12 strian are highly homologous. The homology of gene nucleotide sequence is 97.8%, 99.7% and 97.8%respectively. The sequence of amino acid is 98. 7%, 99.3% and 98.0% respectively. The amino sequences of fimH is analysed by DNA-STAR software. The results indicate that there is no significant variation of fimH protein epitope.