Noegel A, Rdest U, Springer W, Goebel W
Mol Gen Genet. 1979 Oct 1;175(3):343-50. doi: 10.1007/BF00397234.
The synthesis and secretion of the toxic exoprotein alpha-haemolysin of E. coli PM152 is coded by the transmissible plasmid pHly152 (41 x 10(6) dalton) as shown by the transformation of the plasmid DNA and the isolation of mutants that are specifically altered in the synthesis and transport of haemolysin. These mutants were obtained by chemical mutagenesis and insertion of the ampicillin transposon (Tn3) into pHly152. Tn3 transposition was also used for the identification and the location of the cistrons on pHly152 essential for haemolysis. The EcoRI and HindIII fragments of the haemolytic plasmid pHly152 were cloned and used for the complementation of the haemolysis negative Tn3 insertion mutants. A DNA segment of 3.2 x 10(6) dalton could be thus identified which consists of at least three clustered cistrons necessary for haemolysis. Two of these cistrons are required for the formation of active haemolysin. At least one other cistron seems to be involved in the secretion of active haemolysin through the outer membrane of E. coli. The gene products determined by these cistrons were identified in minicells of E. coli. Their molecular properties were determined and their possible function in the formation and secretion of haemolysin will be discussed.
大肠杆菌PM152的毒性外蛋白α-溶血素的合成与分泌由可传递质粒pHly152（41×10⁶道尔顿）编码，这一点通过质粒DNA的转化以及对溶血素合成和转运发生特异性改变的突变体的分离得以证明。这些突变体是通过化学诱变以及将氨苄青霉素转座子（Tn3）插入pHly152获得的。Tn3转座也用于鉴定pHly152上对溶血至关重要的顺反子的位置。溶血性质粒pHly152的EcoRI和HindIII片段被克隆，并用于对溶血阴性的Tn3插入突变体进行互补。由此可以鉴定出一个3.2×10⁶道尔顿的DNA片段，它由至少三个对溶血必需的成簇顺反子组成。其中两个顺反子是形成活性溶血素所必需的。至少还有一个顺反子似乎参与活性溶血素通过大肠杆菌外膜的分泌。这些顺反子所决定的基因产物在大肠杆菌的微小细胞中得到了鉴定。确定了它们的分子特性，并将讨论它们在溶血素形成和分泌中的可能功能。
