三种细菌HPI核心区ybtE基因核苷酸序列及推导氨基酸序列的比较研究

目的比较三种肠聚集性大肠埃希菌、小肠结肠炎耶尔森菌和鼠疫耶尔森菌HPI毒力岛核心区ybtE基因的同源性。方法PCR扩增肠聚集性大肠埃希菌(EAEC)17-2ybtE基因的完整序列,克隆后测序。用ABIPRISM软件对该ybtE基因序列与已知的鼠疫耶尔森菌HPI的ybtE基因以及小肠结肠炎耶尔森菌HPI的irp5基因进行核苷酸序列和推导氨基酸序列比较。结果核苷酸序列,EAEC17-2与鼠疫耶尔森菌及小肠结肠炎耶尔森菌之间的同源性分别为99.8%和98.2%,鼠疫耶尔森菌与小肠结肠炎耶尔森菌之间的同源性为98.2%;推导氨基酸序列,EAEC17-2与鼠疫耶尔森菌及小肠结肠炎耶尔森菌之间的同源性分别为99.8%和97.6%,鼠疫耶尔森菌与小肠结肠炎耶尔森菌之间的同源性为97.8%。结论ybtE基因作为HPI的功能基因高度保守,EAEC中的HPI可能来源于YpsHPI。

Comparison of ybtE nucleotide sequence and deduced amino-acid sequence from EAEC HPI,Yps HPI and Yen HPI

Objective To compare the homogenicity of ybtE gene among EAEC HPI,Yen HPI and Yps HPI.Methods According to the published nucleotide sequence of irp5 gene,the primers were designed.Using polymerase chain reaction(PCR) technique,the gene of ybtE was specifically amplified from the genomic DAN of EAEC 17-2.The gene was cloned and sequenced.Then nucleotide sequence and deduced amino-acid sequence homogenicity of ybtE from EAEC,Yps HPI and Yen HPI were analyzed with ABIPRISM software.Results The homogenicity of nucleotide sequence were 99.8%,98.2% and 98.2% for EAEC vs Yps HPI,EAEC vs Yen HPI and Yps HPI vs Yen HPI,respectively.The homogenicity of deduced amino-acid nucleotide sequence were 99.8%,97.6% and 97.8% for EAEC vs Yps HPI,EAEC vs Yen HPI and Yps HPI vs Yen HPI,respectively.Conslusion As an important functional gene in HPI,ybtE gene is highly conservative.EAEC HPI may come from Yps HPI.