Schumacher G, Ehring R
Institut für Genetik der Universität zu Köln, Köln, Germany.
Mol Gen Genet. 1975;136(1):41-54. doi: 10.1007/BF00275447.
From a DNA-directed cell-free system, functional gal mRNA is obtained which directs the cell-free synthesis of the three galactose enzymes of Escherichia coli. A substantial fraction of this gal mRNA has the properties of a polycistronic messenger. Exposure to elevated temperatures in the presence or absence of magnesium ion results in pronounced changes of the capacity of this mRNA to give rise to the synthesis of the three enzymes. Depending on the conditions of the pre-treatment, the absolute amounts as well as the ratio of the three gene products synthesized can be changed. The different forms of gal messenger so obtained also exhibit different susceptibilities towards functional inactivation during the enzyme synthesis reaction. As the changes in template activity are reversible, it is concluded that the different treatments cause reversible transitions between different conformations of the gal mRNA.
从一个由DNA指导的无细胞系统中，可获得功能性半乳糖（gal）信使核糖核酸（mRNA），它能指导无细胞体系中大肠杆菌三种半乳糖酶的合成。这种gal mRNA的很大一部分具有多顺反子信使的特性。在有或没有镁离子存在的情况下，暴露于高温会导致这种mRNA指导三种酶合成的能力发生显著变化。根据预处理条件，可以改变三种基因产物合成的绝对量以及它们之间的比例。如此获得的不同形式的gal信使在酶合成反应过程中对功能失活也表现出不同的敏感性。由于模板活性的变化是可逆的，因此可以得出结论，不同的处理导致gal mRNA不同构象之间的可逆转变。
