Hasan G, Turner M J, Cordingley J S
Gene. 1984 Jan;27(1):75-86. doi: 10.1016/0378-1119(84)90240-3.
There are six small ribosomal RNAs in trypanosome ribosomes. sRNA3 and sRNA5 of Trypanosoma brucei brucei have been partially sequenced. Sequence homologies indicate that sRNA3 is 5.8S RNA and sRNA5 is 5S RNA of T. b. brucei. The regions specifying these two, and the remaining four small RNAs, have been identified within clones of rRNA genes and in the genome. Five of the small RNAs, 1, 2, 3, 4 and 6, hybridise exclusively within the major rRNA gene repeat. A map of the regions specifying these small RNAs is presented. sRNA3 (5.8S RNA) hybridises to a region corresponding to the transcribed spacer of other eukaryotes. sRNA1 hybridises to a region between sequences specifying the two large subunit RNA molecules of 2.3 kb and 1.8 kb. Sequences specifying sRNAs 2 and 4 are present near the sequence specifying sRNA1, while sRNA6 appears to be specified 3' to the sequence specifying the 1.8-kb RNA sequence. In addition regions of secondary hybridisation for small RNAs 2, 3, 4 and 6 have also been identified. Though sRNA5 (5S RNA) hybridises within the major rRNA repeat, a separate 5S RNA gene repeat with unit size of 760 bp is also present. It is 10 to 20 times more abundant than the major rRNA gene repeat.
锥虫核糖体中有六种小核糖体RNA。布氏布氏锥虫的sRNA3和sRNA5已进行了部分测序。序列同源性表明，sRNA3是布氏布氏锥虫的5.8S RNA，sRNA5是5S RNA。在rRNA基因克隆和基因组中已鉴定出指定这两种以及其余四种小RNA的区域。其中五种小RNA，即1、2、3、4和6，仅在主要rRNA基因重复序列内杂交。给出了指定这些小RNA的区域图谱。sRNA3（5.8S RNA）与对应于其他真核生物转录间隔区的区域杂交。sRNA1与指定2.3 kb和1.8 kb的两个大亚基RNA分子的序列之间的区域杂交。指定sRNA 2和4的序列位于指定sRNA1的序列附近，而sRNA6似乎在指定1.8 kb RNA序列的序列的3'端。此外，还鉴定出了小RNA 2、3、4和6的二级杂交区域。尽管sRNA5（5S RNA）在主要rRNA重复序列内杂交，但也存在一个单独的5S RNA基因重复序列，其单位大小为760 bp。它比主要rRNA基因重复序列丰富10到20倍。
