Chang D D, Clayton D A
Department of Pathology, Stanford University School of Medicine, California 94305-5324.
Cell. 1989 Jan 13;56(1):131-9. doi: 10.1016/0092-8674(89)90991-4.
Using complementary oligonucleotide probes, we have isolated the nuclear gene for the RNA moiety of RNAase MRP; it is present as a single copy and encodes an uncapped primary transcript of 275 nucleotides. Direct sequence analysis revealed that the 136 nucleotide RNA that copurifies with RNAase MRP represents the 3' half of the 275 nucleotide primary transcript. The 5'-flanking region of the gene has putative transcriptional control elements homologous to the promoters of RNA polymerase II-transcribed U-series snRNA genes; however, the coding region possesses a box A sequence and terminates at four T residues, both features characteristic of polymerase III-transcribed genes. A decamer sequence, 5'-CGA-CCCCUCC-3', complementary to a conserved sequence adjacent to the enzymatic cleavage site on the mitochondrial RNA substrate, is present in the RNAase MRP RNA. Isolation of a nuclear gene for the RNA component of a mitochondrial enzyme implies that nucleic acids can be transported across mitochondrial membranes.
利用互补寡核苷酸探针，我们分离出了核糖核酸酶MRP的RNA部分的核基因；它以单拷贝形式存在，编码一个275个核苷酸的无帽初级转录本。直接序列分析表明，与核糖核酸酶MRP共纯化的136个核苷酸的RNA代表了275个核苷酸初级转录本的3' 端一半。该基因的5' 侧翼区域具有与RNA聚合酶II转录的U系列snRNA基因启动子同源的推定转录控制元件；然而，编码区域具有A框序列并在四个T残基处终止，这两个特征都是聚合酶III转录基因所特有的。核糖核酸酶MRP RNA中存在一个十聚体序列5'-CGA-CCCCUCC-3'，它与线粒体RNA底物上酶切位点相邻的保守序列互补。线粒体酶的RNA成分的核基因的分离意味着核酸可以跨线粒体膜运输。
