Brown J W, Nolan J M, Haas E S, Rubio M A, Major F, Pace N R
Department of Microbiology, North Carolina State University, Raleigh 27695, USA.
Proc Natl Acad Sci U S A. 1996 Apr 2;93(7):3001-6. doi: 10.1073/pnas.93.7.3001.
PCR amplification of template DNAs extracted from mixed, naturally occurring microbial populations, using oligonucleotide primers complementary to highly conserved sequences, was used to obtain a large collection of diverse RNase P RNA-encoding genes. An alignment of these sequences was used in a comparative analysis of RNase P RNA secondary and tertiary structure. The new sequences confirm the secondary structure model based on sequences from cultivated organisms (with minor alterations in helices P12 and P18), providing additional support for nearly every base pair. Analysis of sequence covariation using the entire RNase P RNA data set reveals elements of tertiary structure in the RNA; the third nucleotides (underlined) of the GNRA tetraloops L14 and L18 are seen to interact with adjacent Watson-Crick base pairs in helix P8, forming A:G/C or G:A/U base triples. These experiments demonstrate one way in which the enormous diversity of natural microbial populations can be used to elucidate molecular structure through comparative analysis.
使用与高度保守序列互补的寡核苷酸引物，对从混合的天然微生物群体中提取的模板DNA进行PCR扩增，以获得大量不同的核糖核酸酶P RNA编码基因。这些序列的比对被用于核糖核酸酶P RNA二级和三级结构的比较分析。新序列证实了基于培养生物序列的二级结构模型（螺旋P12和P18有微小改变），几乎为每个碱基对提供了额外支持。使用整个核糖核酸酶P RNA数据集进行序列共变分析，揭示了RNA中的三级结构元件；GNRA四环L14和L18的第三个核苷酸（下划线）与螺旋P8中相邻的沃森-克里克碱基对相互作用，形成A:G/C或G:A/U碱基三联体。这些实验证明了一种利用天然微生物群体的巨大多样性，通过比较分析来阐明分子结构的方法。
