Fernández A
Department of Biochemistry and Molecular Biology, Medical School, Miami, FL 33101-6129.
Biophys Chem. 1992 Nov;45(1):27-30. doi: 10.1016/0301-4622(92)87020-j.
We simulate the sequential folding of an autocatalytic pre-mRNA of group I revealing a scenario where core elements exert their function on intramolecular substrates as they are being generated. Our results indicate that the interactions shaping the 3'-substrate do not coexist with those shaping the 5'-substrate, but form after 5'-cleavage has occurred. This chronology of events is shown to be required for ribozyme function and quite universal in group I introns, since it is based on a competition of conserved helical stems. Preliminary probes rooted in site-directed mutagenesis are invoked to further validate the results.
我们模拟了I组自催化前体mRNA的顺序折叠过程，揭示了一种情况，即核心元件在分子内底物产生时就对其发挥作用。我们的结果表明，形成3'-底物的相互作用并非与形成5'-底物的相互作用同时存在，而是在5'-切割发生后形成。事实证明，这种事件发生顺序对于核酶功能是必需的，并且在I组内含子中相当普遍，因为它基于保守螺旋茎的竞争。我们采用基于定点诱变的初步探索来进一步验证这些结果。
