Meysick Karen C, Seidman Jessica, Falconio Jason R
Division of Bacterial, Laboratory of Respiratory and Special Pathogens, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
Microb Pathog. 2009 Jul;47(1):24-32. doi: 10.1016/j.micpath.2009.04.008. Epub 2009 May 3.
Analysis of the Yersinia pseudotuberculosis and Yersinia pestis genomes indicates that both species carry an identical copy of a gene that is predicted to encode a protein which shares 80% similarity to the Yersinia enterocolitica YplA, a secreted phospholipase that has been shown to contribute to virulence. In contrast to well tolerated production of the Y. enterocolitica YplA in Escherichia coli, Y. pseudotuberculosis YplA expression was found to be toxic; however, cell viability could be restored if the Y. pseudotuberculosis YplA was expressed in the presence of its accessory protein YplB. In vitro, Y. pseudotuberculosis YplB was shown to reduce the activity of its cognate phospholipase in a dose-dependent manner. To determine whether the Y. pseudotuberculosis and Y. enterocolitica YplAs were secreted and regulated in a similar manner, secretion and promoter activity assays were performed. Unlike the situation apparent in Y. enterocolitica, expression of the Y. pseudotuberculosis yplA gene did not appear to be controlled by the flagellar regulon, nor did the phospholipase appear to be efficiently exported through the flagellar apparatus. These results indicate that the Yersinia YplAs vary in many of their attributes despite their high degree of amino acid homology.
对假结核耶尔森菌和鼠疫耶尔森菌基因组的分析表明，这两个物种都携带一个相同的基因拷贝，该基因预计编码一种蛋白质，与小肠结肠炎耶尔森菌YplA有80%的相似性，YplA是一种已被证明有助于毒力的分泌型磷脂酶。与在大肠杆菌中能良好耐受的小肠结肠炎耶尔森菌YplA的产生不同，假结核耶尔森菌YplA的表达被发现具有毒性；然而，如果假结核耶尔森菌YplA在其辅助蛋白YplB存在的情况下表达，细胞活力可以恢复。在体外，假结核耶尔森菌YplB被证明以剂量依赖的方式降低其同源磷脂酶的活性。为了确定假结核耶尔森菌和小肠结肠炎耶尔森菌YplA是否以类似的方式分泌和调控，进行了分泌和启动子活性分析。与小肠结肠炎耶尔森菌中明显的情况不同，假结核耶尔森菌yplA基因的表达似乎不受鞭毛调节子的控制，磷脂酶似乎也没有通过鞭毛装置有效地输出。这些结果表明耶尔森菌YplA尽管氨基酸同源性很高，但在许多特性上存在差异。
