Norel F, Coynault C, Miras I, Hermant D, Popoff M Y
Institut Pasteur, Service des Entérobactéries, Unité INSERM 199, Paris, France.
Mol Microbiol. 1989 Jun;3(6):733-43. doi: 10.1111/j.1365-2958.1989.tb00222.x.
A 22kb region of the 90kb virulence-associated plasmid, pIP1350, of Typhimurium strain C52 was cloned into the mobilizable vector pSUP202, yielding plasmid pIP1352. This recombinant plasmid restored full virulence to plasmidless strain C53 in a mouse model. Transposon Tn5 insertion mutagenesis demonstrated the existence of two DNA sequences in pIP1352 designated VirA and VirB, both of which are essential for the expression of virulence. A recombinant plasmid containing only the VirA and VirB regions markedly increased the virulence of the plasmidless strain C53, but did not confer full virulence. These results suggested that a third virulence-associated region might be present on pIP1352. Eleven proteins encoded by the 22kb insert sequence of pIP1352 were identified in Escherichia coli SE5000 maxicells. The VirA region encoded at least two proteins with apparent molecular weights of 71,000 and 28,000 and the VirB region encoded two proteins of 43,000 and 38,000.
将鼠伤寒沙门氏菌C52株90kb毒力相关质粒pIP1350的一个22kb区域克隆到可移动载体pSUP202中，得到质粒pIP1352。在小鼠模型中，该重组质粒使无质粒菌株C53恢复了完全毒力。转座子Tn5插入诱变表明pIP1352中存在两个DNA序列，分别命名为VirA和VirB，二者对毒力表达均至关重要。仅包含VirA和VirB区域的重组质粒显著增加了无质粒菌株C53的毒力，但未赋予其完全毒力。这些结果表明pIP1352上可能存在第三个毒力相关区域。在大肠杆菌SE5000大细胞中鉴定出了由pIP1352的22kb插入序列编码的11种蛋白质。VirA区域编码至少两种表观分子量分别为71,000和28,000的蛋白质，VirB区域编码两种分子量分别为43,000和38,000的蛋白质。
