Peng H L, Novick R P, Kreiswirth B, Kornblum J, Schlievert P
Public Health Research Institute, New York, New York 10016.
J Bacteriol. 1988 Sep;170(9):4365-72. doi: 10.1128/jb.170.9.4365-4372.1988.
We have previously identified a gene in Staphylococcus aureus, agr, whose activity is required for high-level post-exponential-phase expression of a series of secreted proteins. In this paper, we describe the cloning of this gene in Escherichia coli by using an inserted transposon (Tn551) as a cloning probe. The cloned gene, consisting of a 241-codon open reading frame containing the site of the transposon insertion, was recloned to an S. aureus vector, pSK265, and shown to be functional in S. aureus. Activity was evaluated by determinations of alpha-hemolysin, beta-hemolysin, and toxic shock syndrome toxin-1 production in early-stationary-phase cultures. The cloned gene showed considerable variation with respect to different exoproteins and different host strains compared with the chromosomal agr determinant; this variation could not be attributed to the higher copy number of the cloned gene and probably reflects inapparent subtleties of the regulatory system.
我们之前在金黄色葡萄球菌中鉴定出一个基因——agr，该基因的活性是一系列分泌蛋白在指数生长期后高水平表达所必需的。在本文中，我们描述了通过使用插入的转座子（Tn551）作为克隆探针，将该基因克隆到大肠杆菌中的过程。克隆的基因由一个241个密码子的开放阅读框组成，其中包含转座子插入位点，该基因被重新克隆到金黄色葡萄球菌载体pSK265中，并证明在金黄色葡萄球菌中具有功能。通过测定早期稳定期培养物中α-溶血素、β-溶血素和毒性休克综合征毒素-1的产生来评估活性。与染色体上的agr决定簇相比，克隆的基因在不同的外毒素和不同的宿主菌株方面表现出相当大的差异；这种差异不能归因于克隆基因的较高拷贝数，可能反映了调节系统不明显的细微之处。
