摘要
鸡大肠杆菌1型菌毛是一种重要的致病因子,可以黏附到家禽机体的呼吸道上皮,从而引起机体发病。1型菌毛基因簇由fimB,fimE,fimA,fimI,fimC,fimD,fimF,fimG和fimH等组成。在国外K12株大肠杆菌1型菌毛fimE基因是一个大小为为555 bp,具有相变开关功能的片段,我国鸡源大肠杆菌1型菌毛fimE基因序列尚未见报道。本研究通过聚合酶链式反应扩增、克隆到了鸡大肠杆菌MG10株1型菌毛的fimE基因,测定了基因序列,并运用相关软件将其翻译成氨基酸序列。通过对fimE基因序列分析比较及对fimE蛋白进行预测分析,发现鸡大肠杆菌与K12大肠杆菌1型菌毛的fimE基因之间的同源性达到99.1%以上;亲水性、抗原性预测表明,二者之间都存在密切的相似相关性。结果表明,核酸同源性为99.5%。fimE基因的核苷酸序列中有5个核苷酸残基发生了改变,而预测氨基酸序列变化仅第184位氨基酸由缬氨酸V变为丙氨酸A;其余无核苷酸的变化。
Type 1 pili in avian Escherichia coli is a virulent factor that triggers urinary tract＇s infection and degranulation by attaching the respiratory epithelium of chickens.The gene which regulates type 1 pili contains such subunits as fimB,fimE,fimA,fimI,fimC,fimD,fimF,fimG and fimH.According to the foreign study,fimE of type 1 pili in Escherichia coli K12 is a segment of 555 bp DNA with switch function while there are no gene reports on fimE in our country.In this study,through polymerases chain reaction,the fimE gene is amplified by PCR using the DNA template of Escherichia coli MG10,then the PCR product is cloned and the nucleotide sequence is determined through related software analysis.It is found that nucleotide sequence of fimE gene both in avian Escherichia coli and K-12 strians are highly homologous,reaching 99.1%.The prediction of sequence translated into amino acid shows that there is close similarity between hydrophilicity and antigenicity.The homology of gene nucleotide sequence is 99.5%,Five nucleotide residues have been changed in nucleotide sequence and only 1 amino acid V is replaced by A on the 184th bite.
出处
《金陵科技学院学报》
2010年第4期67-72,共6页
Journal of Jinling Institute of Technology
基金
江苏省自然科学基金资助(BK2008059)
