Shiraishi H, Shimura Y
EMBO J. 1986 Dec 20;5(13):3673-9. doi: 10.1002/j.1460-2075.1986.tb04698.x.
The effect of structural changes on the functions of the RNA component (M1 RNA) of ribonuclease P (RNase P) of Escherichia coli has been studied using the thermosensitive mutants of the rnpB gene. One of the mutants, ts709, has two G--A substitutions at positions 89 and 365 from the 5' end of M1 RNA. Of these substitutions, the one at position 89 from the 5' end is responsible for the phenotype of this mutant. Although the RNase P activity of ts709 is thermosensitive, the mutant M1 RNA has the same catalytic activity as the wild-type RNA. M1 RNA of another mutant, ts2418, has a G--A substitution at position 329. This mutant RNA has extremely low catalytic activity. The upstream mutational site of ts709 appears to play a role in the association with the protein subunit, whereas the mutational site of ts2418 is related to the catalytic function of M1 RNA.
利用核糖核酸酶P（RNase P）的rnpB基因的温度敏感突变体，研究了结构变化对大肠杆菌核糖核酸酶P（RNase P）的RNA组分（M1 RNA）功能的影响。其中一个突变体ts709，在M1 RNA 5'端第89位和第365位有两个G→A替换。在这些替换中，5'端第89位的替换导致了该突变体的表型。虽然ts709的RNase P活性是温度敏感的，但突变的M1 RNA与野生型RNA具有相同的催化活性。另一个突变体ts2418的M1 RNA在第329位有一个G→A替换。这种突变RNA具有极低的催化活性。ts709的上游突变位点似乎在与蛋白质亚基的结合中起作用，而ts2418的突变位点与M1 RNA的催化功能有关。
