Götz F, Zabielski J, Philipson L, Lindberg M
Plasmid. 1983 Mar;9(2):126-37. doi: 10.1016/0147-619x(83)90015-x.
A 29.5-kb plasmid, pSX267, from Staphylococcus xylosus DSM 20267 was found to code for arsenate, arsenite, and antimony (III) resistance. The isolated plasmid was transformed into S. aureus, where the same resistances were expressed. It was of special interest to see whether pSX267 showed any DNA sequence homology with the well-studied penicillinase plasmid from S. aureus pI258, also conferring arsenate, arsenite, and antimony III resistance. By the use of the Southern blotting technique, it was found that DNA sequence homology exists in the region of arsenate, arsenite, and antimony resistance, in addition to the region where the origin of replication, the incompatibility, and the replication A function were mapped on pI258. This finding was confirmed by electron microscope heteroduplex analysis, which allowed a correlation between the genetic and physical maps of pI258 and pSX267. Duplex DNA was formed at the arsenate operon of pI258, with a length of 2.6 kb, and at the incompatibility and replication A region, comprising a length of 2.5 kb. Adjacent to this latter region, two small regions of DNA homology were present, with lengths of 0.2 and 0.27 kb. Both plasmids share approximately 20% DNA sequence homology. The DNA homology of the arsenate, arsenite, and antimony III resistance coding regions between pI258 and pSX267 indicate that these plasmid-determined resistance markers are highly conserved and distributed among different staphylococcal species.
从木糖葡萄球菌DSM 20267中分离出的一个29.5 kb的质粒pSX267被发现编码对砷酸盐、亚砷酸盐和锑（III）的抗性。将分离出的质粒转化到金黄色葡萄球菌中，该菌表达了相同的抗性。特别令人感兴趣的是，pSX267与已被深入研究的来自金黄色葡萄球菌的青霉素酶质粒pI258是否存在任何DNA序列同源性，pI258也赋予对砷酸盐、亚砷酸盐和锑（III）的抗性。通过Southern印迹技术发现，除了在pI258上绘制了复制起点、不相容性和复制A功能的区域外，在砷酸盐、亚砷酸盐和锑抗性区域也存在DNA序列同源性。这一发现通过电子显微镜异源双链分析得到证实，该分析使得能够建立pI258和pSX267的遗传图谱与物理图谱之间的相关性。在pI258的砷酸盐操纵子处形成了长度为2.6 kb的双链DNA，在不相容性和复制A区域形成了长度为2.5 kb的双链DNA。在后者区域相邻处，存在两个长度分别为0.2和0.27 kb的小DNA同源区域。两种质粒共享约20%的DNA序列同源性。pI258和pSX267之间砷酸盐、亚砷酸盐和锑（III）抗性编码区域的DNA同源性表明，这些由质粒决定的抗性标记高度保守，并在不同的葡萄球菌物种中分布。
