RNA heptamers that direct RNA cleavage by mammalian tRNA 3′ processing endoribonuclease
RNA heptamers that direct RNA cleavage by mammalian tRNA 3′ processing endoribonuclease
复制标题
DOI：
10.1093/nar/26.11.2565
复制
发表时间：
1998-06-01
影响因子：
14.9
通讯作者：
Kaspar, R
中科院分区：
文献类型：
--
作者：
Nashimoto, M;Geary, S;Kaspar, R
哺乳动物tRNA 3 '加工核糖核酸内切酶（3' tRNase）可以识别并切割任何与另一RNA形成前体tRNA样复合物的靶RNA。测试了各种RNA分子组以鉴定可以通过3 'tRNase指导靶RNA切割的最小RNA。在存在小的5 '半tRNA（Arg）变体的情况下，3'半tRNA（Arg）被3 'tRNase有效地切割，所述小的5'半tRNA（Arg）变体的D茎环区被部分缺失。3 'tRNase在5' tRNA（Arg）存在下也切割3 '半tRNA（Arg）。仅由受体茎区组成，其催化效率与由完整的5 '半tRNA（Arg）指导的切割相当。由七聚体指导的切割的催化效率随着3 '半tRNA（Arg）变体的T茎环结构的稳定性降低而降低。没有检测到无T茎碱基对的3 '半tRNA（Arg）的七聚体定向切割。七聚体还指导含有稳定发夹结构的HIV-1 RNA的切割。这些发现表明，在存在RNA七聚体的情况下，3 'tRNase可以从大的复杂RNA库中区分并消除具有与七聚体结合序列相邻的稳定发夹的靶RNA。
Mammalian tRNA 3' processing endoribonuclease (3' tRNase) can recognize and cleave any target RNA that forms a precursor tRNA-like complex with another RNA. Various sets of RNA molecules were tested to identify the smallest RNA that can direct target RNA cleavage by 3' tRNase. A 3' half tRNA(Arg) was cleaved efficiently by 3' tRNase in the presence of small 5' half tRNA(Arg) variants, the D stem-loop region of which was partially deleted, Remarkably, 3' tRNase also cleaved the 3' half tRNA(Arg) in the presence of a 7 nt 5' tRNA(Arg) composed only of the acceptor stem region with a catalytic efficiency comparable with that of cleavage directed by an intact 5' half tRNA(Arg). The catalytic efficiency of cleavage directed by the heptamer decreased as the stability of the T stem-loop structures of 3' half tRNA(Arg) variants decreased. No heptamer-directed cleavage of a 3' half tRNA(Arg) without T stem base pairs was detected. A heptamer also directed cleavage of an HIV-1 RNA containing a stable hairpin structure. These findings suggest that in the presence of an RNA heptamer, 3' tRNase can discriminate and eliminate target RNAs that possess a stable hairpin adjacent to the heptamer binding sequence from a large complex RNA pool.