Wagner W, Vogel M, Goebel W
J Bacteriol. 1983 Apr;154(1):200-10. doi: 10.1128/jb.154.1.200-210.1983.
Among a large collection of hemolysis-negative mutants obtained by mutagenesis of the Hly plasmid pHly152 with Tn5, we have isolated two classes of mutants which are defective in the transport of hemolysin across the outer membrane. The two cistrons (hylBa and hlyBb) which are affected in these mutants are located adjacent to each other on the hly determinant but are transcribed from different promoters. Recombinant plasmids were constructed which carry the two functions as combined or separated cistrons. These were shown to complement the two types of transport mutants. Studies on the compartmentation of hemolysin in these two classes of mutants indicate that most hemolysin (greater than 70%) in hlyBa mutants is located in the periplasmic space, whereas in hlyBb mutants a larger portion of hemolysin is associated with the outer membrane fraction. The phenotypic appearance of colonies from hlyBb mutants is that of beta-hemolytic Escherichia coli strains, indicating that a substantial portion of hemolysin has already reached the outside of the outer membrane without being released into the medium. Release was achieved readily when hlyBb mutants were complemented with a recombinant plasmid carrying hlyBb.
在用Tn5对溶血素质粒pHly152进行诱变获得的大量溶血阴性突变体中，我们分离出了两类在外膜运输溶血素方面存在缺陷的突变体。在这些突变体中受影响的两个顺反子（hylBa和hlyBb）在hly决定簇上彼此相邻，但由不同的启动子转录。构建了携带这两种功能的重组质粒，它们作为组合或分离的顺反子存在。这些重组质粒被证明可互补这两种类型的运输突变体。对这两类突变体中溶血素分隔情况的研究表明，hlyBa突变体中大多数溶血素（大于70%）位于周质空间，而在hlyBb突变体中，较大比例的溶血素与外膜部分相关。hlyBb突变体菌落的表型类似于β溶血大肠杆菌菌株，这表明相当一部分溶血素已经到达外膜外部但未释放到培养基中。当hlyBb突变体用携带hlyBb的重组质粒互补时，溶血素很容易释放。
