Research Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
Nat Chem Biol. 2013 Oct;9(10):616-22. doi: 10.1038/nchembio.1320. Epub 2013 Aug 25.
Protein sequences are diversified on the DNA level by recombination and mutation and can be further increased on the RNA level by alternative RNA splicing, involving introns that have important roles in many biological processes. The protein version of introns (inteins), which catalyze protein splicing, were first reported in the 1990s. The biological roles of protein splicing still remain elusive because inteins neither provide any clear benefits nor have an essential role in their host organisms. We now report protein alternative splicing, in which new protein sequences can be produced by protein recombination by intermolecular domain swapping of inteins, as elucidated by NMR spectroscopy and crystal structures. We demonstrate that intein-mediated protein alternative splicing could be a new strategy to increase protein diversity (that is, functions) without any modification in genetic backgrounds. We also exploited it as a post-translational protein conformation-driven switch of protein functions (for example, as highly specific protein interference).
蛋白质序列在 DNA 水平上通过重组和突变进行多样化，并可通过选择性 RNA 剪接在 RNA 水平上进一步增加，其中内含子在许多生物过程中起着重要作用。首先在 20 世纪 90 年代报道了催化蛋白质剪接的内含子（intein）的蛋白质版本。由于内含子既没有提供任何明显的好处，也没有在其宿主生物体中发挥重要作用，因此蛋白质剪接的生物学作用仍然难以捉摸。我们现在报告蛋白质的选择性剪接，其中新的蛋白质序列可以通过内含子的分子间结构域交换的蛋白质重组产生，如通过 NMR 光谱和晶体结构阐明的那样。我们证明，通过内含子介导的蛋白质选择性剪接可以作为一种新策略，在不改变遗传背景的情况下增加蛋白质多样性（即功能）。我们还将其用作蛋白质功能的构象驱动的蛋白质后翻译开关（例如，作为高度特异性的蛋白质干扰）。
