Leontis N, DaLio A, Strobel M, Engelke D
Department of Biological Chemistry, University of Michigan, Ann Arbor 48109.
Nucleic Acids Res. 1988 Mar 25;16(6):2537-52. doi: 10.1093/nar/16.6.2537.
RNase P derived from S. cerevisiae nuclei was tested for its ability to cleave a variety of naturally occurring and selectively altered precursor-tRNA molecules to yield matured 5' termini. Precursors were synthesized in vitro in order to test which aspects of substrate structure are crucial to recognition and cleavage by RNase P. Base modifications in the precursor substrates are not required for cleavage by the enzyme, but deletion and substitution mutations affecting any portion of the precursor tertiary structure reduce cleavage. In particular, a number of alterations in the intervening sequence (IVS) reduce the susceptibility of the substrate to cleavage by RNase P. The significance of these results is discussed in reference to the contribution of the IVS to the structure of the precursor-tRNA.
对源自酿酒酵母细胞核的核糖核酸酶P（RNase P）进行了测试，以检验其切割各种天然存在的以及经过选择性改变的前体tRNA分子从而产生成熟5'末端的能力。为了测试底物结构的哪些方面对于RNase P的识别和切割至关重要，前体是在体外合成的。酶切割前体底物时不需要碱基修饰，但影响前体三级结构任何部分的缺失和取代突变会降低切割效率。特别是，间隔序列（IVS）中的一些改变会降低底物对RNase P切割的敏感性。结合IVS对前体tRNA结构的贡献对这些结果的意义进行了讨论。
