Solari A, Deutscher M P
Mol Cell Biol. 1983 Oct;3(10):1711-7. doi: 10.1128/mcb.3.10.1711-1717.1983.
A survey of RNases in Xenopus laevis oocytes has been carried out to identify potential tRNA-processing enzymes in this system. Using a variety of specific and nonspecific substrates, we have shown that oocytes contain multiple RNases with various specificities. Three activities that could cleave the extraneous residues from the artificial tRNA precursor, tRNA-C-[14C]U-C, to generate a substrate for -C-C-A addition by tRNA nucleotidyltransferase were identified. One of these was a cytoplasmic exonuclease which generated predominantly tRNA-C, whereas the other two were nuclear endonucleases which cleaved the precursor to generate tRNA-N. The possible involvement of these activities in 3' tRNA processing in oocytes is discussed.
为了鉴定非洲爪蟾卵母细胞系统中潜在的tRNA加工酶,我们对其中的核糖核酸酶进行了一项调查。使用多种特异性和非特异性底物,我们发现卵母细胞中含有多种具有不同特异性的核糖核酸酶。我们鉴定出了三种活性,它们能够从人工tRNA前体tRNA-C-[14C]U-C上切割多余的残基,从而生成一种底物,供tRNA核苷酸转移酶添加-C-C-A。其中一种是细胞质外切核酸酶,主要生成tRNA-C,而另外两种是细胞核内切核酸酶,它们切割前体以生成tRNA-N。本文讨论了这些活性在卵母细胞3'端tRNA加工过程中可能发挥的作用。