Naykova Tatiana M, Kondrakhin Yuri V, Rogozin Igor B, Voevoda Mikhail I, Yudin Nikolai S, Romaschenko Aida G
Laboratory of Animal Molecular Genetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentyeva Avenue, 630090, Novosibirsk, Russia.
J Mol Evol. 2003 Nov;57(5):520-32. doi: 10.1007/s00239-003-2504-8.
RNA polymerase III promoter is located within the coding region in all eukaryotic tRNA genes, whereas in prokaryotic tRNA genes, the promoter is located upstream of the transcription initiation site. We analyzed the nucleotide sequence context of the A and B boxes of RNA polymerase III promoters from different unicellular eukaryotes, plants, and animals and the homologous sequences in the tRNA genes of prokaryotic species (Archaea, Eubacteria). The long and short sequence variants of the A box are nonrandomly distributed across different types of the eukaryotic tRNA genes. In contrast, the sequences from the prokaryotic counterparts of the long and short variants are randomly scattered among prokaryotic tRNA genes. The sequence diversity of the 3' portion of the A box in the eukaryotic tRNA genes was sharply reduced compared to that of the homologous segments of the prokaryotic tRNA genes. Analysis of the frequencies of oligonucleotide variants from different parts of the A box suggested that the prominent changes in the structure of the A box occurred at about the same time in all tRNA genes during the prokaryote eukaryote evolutionary transition.
RNA聚合酶III启动子在所有真核生物tRNA基因中位于编码区内，而在原核生物tRNA基因中，启动子位于转录起始位点上游。我们分析了来自不同单细胞真核生物、植物和动物的RNA聚合酶III启动子的A盒和B盒的核苷酸序列背景以及原核生物（古细菌、真细菌）tRNA基因中的同源序列。A盒的长序列变体和短序列变体在不同类型的真核生物tRNA基因中呈非随机分布。相比之下，长变体和短变体的原核对应序列在原核生物tRNA基因中随机散布。与原核生物tRNA基因的同源片段相比，真核生物tRNA基因中A盒3'部分的序列多样性大幅降低。对A盒不同部分的寡核苷酸变体频率的分析表明，在原核生物向真核生物的进化转变过程中，所有tRNA基因中A盒结构的显著变化大致同时发生。
