Nuc P, Nuc K, Szweykowska-Kulińska Z, Pawełkiewicz J
Institute of Biochemistry and Biotechnology, University of Agriculture, Poznan, Poland.
Acta Biochim Pol. 1997;44(2):259-74.
A nuclear DNA fragment (7.8 kb) from yellow lupin (L. luteus) was sequenced and shown to contain tRNA(Gly) (GGC) genes and tRNAGly (GGC) pseudogenes organized in three tandemly repeated units: of 2565 bp and 2564 bp, and one, truncated from its 3' end, of 1212 bp. Each unit contains an identical pair of a tRNA(Gly) gene and a pseudogene, both having the same polarity. The nucleotide sequence of the gene appears colinear to L. luteus cytoplasmic tRNA(Gly) (GGC) primary structure. All three genes are efficiently transcribed in HeLa-cell nuclear extract giving two primary transcripts. The main, longer primary transcripts have each an extremely long 3' trailer of about 100 nucleotides, the structure of which is specific only for tRNAGly genes and pseudogenes (80% homology) of the studied tandem (but not for other tRNA(Gly) genes of the yellow lupin genome) as it has been shown by Southern hybridization. This distinctive feature allowed to isolate putative tRNAGly precursor(s) encoded by at least one of the three tRNA(Gly) (GGC) genes from L. luteus seedlings.
对来自黄羽扇豆（L. luteus）的一个7.8 kb核DNA片段进行了测序，结果显示其含有以三个串联重复单元排列的tRNA(Gly) (GGC)基因和tRNAGly (GGC)假基因：一个2565 bp，一个2564 bp，还有一个从3'端截短的1212 bp。每个单元都包含一对相同的tRNA(Gly)基因和假基因，二者具有相同的极性。该基因的核苷酸序列与黄羽扇豆细胞质tRNA(Gly) (GGC)的一级结构呈共线性。所有这三个基因在HeLa细胞核提取物中均能高效转录，产生两种初级转录本。主要的、较长的初级转录本各自都有一个约100个核苷酸的极长3'尾，正如Southern杂交所显示的，其结构仅对所研究串联重复中的tRNAGly基因和假基因（80%同源性）具有特异性（而非黄羽扇豆基因组中的其他tRNA(Gly)基因）。这一独特特征使得能够从黄羽扇豆幼苗中分离出由三个tRNA(Gly) (GGC)基因中至少一个编码的假定tRNAGly前体。
