Knap A K, Wesolowski D, Altman S
Department of Biology, Yale University, New Haven, CT 06520.
Biochimie. 1990 Nov;72(11):779-90. doi: 10.1016/0300-9084(90)90187-l.
Certain nucleotides in M1 RNA, the catalytic RNA subunit of RNase P from E coli, are protected from chemical modification when M1 RNA forms complexes with tRNA precursor molecules (ES complexes). Many of these nucleotides are important in the formation of the Michaelis complex. In the presence of tRNA precursor molecules, the pattern of protection from chemical modification of a region in M1 RNA that resembles the E site in 23S rRNA is similar to the pattern of protection of the E site in the presence of deacylated tRNA. In the complex with the RNA enzyme, more nucleotides in the substrate become accessible to modification, an indication that the substrate is in an unfolded conformation under these conditions.
M1 RNA是来自大肠杆菌的核糖核酸酶P的催化性RNA亚基，当M1 RNA与tRNA前体分子形成复合物（ES复合物）时，其某些核苷酸能免受化学修饰。其中许多核苷酸在米氏复合物的形成中很重要。在tRNA前体分子存在的情况下，M1 RNA中一个类似于23S rRNA中E位点的区域的化学修饰保护模式，与脱酰基tRNA存在时E位点的保护模式相似。在与RNA酶形成的复合物中，底物中有更多的核苷酸可被修饰，这表明在这些条件下底物处于未折叠构象。
