Analysis of the functional role of conserved residues in the protein subunit of ribonuclease P from Escherichia coli
Analysis of the functional role of conserved residues in the protein subunit of ribonuclease P from Escherichia coli
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DOI：
10.1006/jmbi.1997.0906
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发表时间：
1997-04-11
影响因子：
5.6
通讯作者：
Altman, S
中科院分区：
文献类型：
--
作者：
Gopalan, V;Baxevanis, AD;Altman, S
大肠杆菌核糖核酸酶P的催化亚基M1 RNA对前体tRNA和其他一些小细胞RNA的加工在体内外均被C5蛋白（蛋白辅助因子）加速。为了了解蛋白辅因子促进和稳定M1 RNA的某些构象的机制，这些构象对RNase P催化是最有效的，我们使用定点诱变产生C5蛋白的突变衍生物，并评估它们在体内和体外促进RNase P催化的能力。我们的研究结果表明，C5蛋白中某些保守的疏水性和碱性残基对其功能是重要的，C5蛋白中单个氨基酸残基的变化可以改变RNase P全酶的底物特异性。(C)出版社：Academic Press Limited。
The processing of precursor tRNAs and some other small cellular RNAs by M1 RNA, the catalytic subunit of Escherichia coli ribonuclease P, is accelerated by C5 protein (the protein cofactor) both in vitro and in vivo. In an effort to understand the mechanism by which the protein cofactor promotes and stabilizes certain conformations of M1 RNA that are most efficient for RNase P catalysis, we have used site-directed mutagenesis to generate mutant derivatives of C5 protein and assessed their ability to promote RNase P catalysis in vivo and in vitro. Our results indicate that certain conserved hydrophobic and basic residues in C5 protein are important for its function and that single amino acid residue changes in C5 protein can alter the substrate specificity of the RNase P holoenzyme. (C) 1997 Academic Press Limited.