Michaelis S, Guarente L, Beckwith J
J Bacteriol. 1983 Apr;154(1):356-65. doi: 10.1128/jb.154.1.356-365.1983.
Using recombinant DNA techniques, we have constructed phoA-lacZ gene fusions. Two of the fusions encode hybrid proteins containing approximately half of alkaline phosphatase at the amino terminus joined to beta-galactosidase. For the one fusion strain analyzed in detail, it was shown that the hybrid protein is found in the membrane fraction of cells. In its membrane location, the beta-galactosidase activity of the hybrid is not sufficient to support cell growth on lactose. Unexpectedly, fusions containing phoA and lacZ joined in the wrong translational reading frame were also obtained. These fusions direct the phosphate-regulated synthesis of beta-galactosidase, apparently via a translation restart mechanism. Thus, when gene fusions are constructed, the presence of properly regulated beta-galactosidase activity does not necessarily indicate that a hybrid protein is being produced.
利用重组DNA技术，我们构建了phoA-lacZ基因融合体。其中两个融合体编码的杂合蛋白在氨基末端含有约一半的碱性磷酸酶，并与β-半乳糖苷酶相连。对于详细分析的一个融合菌株，结果表明杂合蛋白存在于细胞的膜组分中。在其膜定位中，杂合蛋白的β-半乳糖苷酶活性不足以支持细胞在乳糖上生长。出乎意料的是，我们还获得了phoA和lacZ以错误的翻译阅读框连接的融合体。这些融合体显然通过翻译重新起始机制指导β-半乳糖苷酶的磷酸盐调节合成。因此，构建基因融合体时，受适当调节的β-半乳糖苷酶活性的存在并不一定表明正在产生杂合蛋白。
