摘要
参考GenBank中单核细胞增多性李斯特菌(LM)第I毒力岛(LIPI-1)有关基因序列设计引物,分段扩增、克隆了分离菌株XFL0605LIPI-1毒力岛全基因序列,序列全长8 558 bp,包括完整的prfA、plcA、hly、mpl、actA和plcB6个基因。对LIPI-1编码的6个毒力基因进行序列分析,各毒力基因反映的进化关系不尽一致,表明李斯特菌株在获得外源性毒力基因方面具有不同步性,各毒力基因来源也不尽相同。应用相应软件对各毒力基因编码蛋白的信号肽、跨膜区进行预测,确定了基因序列中调控蛋白PrfA结合区核苷酸序列。分析并确认了hlyA基因及推导氨基酸序列PEST基序和C端保守11肽序列。研究还发现LM菌株XFL0605actA基因编码604个氨基酸,缺失了105 bp富脯氨酸重复片段编码碱基,只有2个E/DFPPPPXD/E重复序列。
The LIPI-1 gene cluster of Listeria monocytogenes isolate strain XFL0605 was segmentally amplified by PCR and sequenced. The results showed that the fragment was 8 558 bp,and containing all the members of the prfA-regulated virulence gene cluster such as prfA, hly, plcA, plcB, mpl and actA. Phylogenetic analysis of the isolate XFL0605 and other reference L. rnonocytogenes, L. seeligeri and L. ivanovii strains based on the gene sequence demonstrated clearly that the evolutionary relationship of strains were different. It revealed that recombination of LIPI-1 has different assembly process. Furthermore, we predicted the signal peptides and transmember domain and their cleavage positions, and investigated the PrfA DNA binding sites of the LIPI-1 virulence genes. The hlyA gene deduced amino acid of XFL0605 contains a PEST-like sequence at the N-terminus, and a conserved undecapeptide, ECTGLAWEWWR, at the C terminus. It also showed that actA gene of XFL0605 encode 604 amino acids but 105 bp nucleotide missing in proline-rich region, only contains two E/DFPPPPXD/E repeat sequences.
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2008年第5期627-633,共7页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
襄樊市科技攻关项目(2006)
湖北出入境检验检疫局科技项目(2006)
