Plant cytosolic tRNAHis possesses an exceptional C54 in the canonical TPsiC loop.
Plant cytosolic tRNAHis possesses an exceptional C54 in the canonical TPsiC loop.
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植物胞质 tRNAHis 在典型的 TPsiC 环中拥有特殊的 C54。
DOI：
10.1093/nar/26.11.2708
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发表时间：
1998
影响因子：
14.9
通讯作者：
I. Small
中科院分区：
文献类型：
--
作者：
K. Akama;Y. Yukawa;M. Sugiura;I. Small
据报道，编码拟南芥tRNAHis的核基因在TPsiC环中含有C54，尽管相应的核苷酸在几乎所有其他tRNA中都是不变的U或衍生物。以前报道的唯一的植物胞质tRNAHis序列，来自羽扇豆，具有U54。为了重新研究植物胞质tRNAHis及其基因，我们使用了DNA和RNA序列分析，PCR扩增的tRNA基因的限制性内切酶消化，RNA杂交和体内氨酰化测定。我们的研究结果表明，拟南芥核tRNAHis基因普遍含有C54，从烟草，羽扇豆和豌豆。C54核苷酸保持在成熟的tRNAHis中，其在体内被氨酰化，但与所检测的其他tRNA相比相对较低。最后，使用源自植物细胞核的体外系统，显示了用T54代替C54的拟南芥tRNAHis基因的转录活性比野生型基因高5倍以上。一个可能的作用，这显然是次优的tRNAHis序列的建议。
A nuclear gene coding for tRNAHis from Arabidopsis has been reported to contain C54in the TPsiC loop, although the corresponding nucleotide is an invariant U or a derivative in nearly all other tRNAs. The only previously reported plant cytosolic tRNAHis sequence, from lupin, has U54. To re-examine plant cytosolic tRNAsHis and their genes we have used DNA and RNA sequence analyses, restriction enzyme digestion of PCR-amplified tRNA genes, RNA hybridization and in vivo aminoacylation assays. Our results suggest that Arabidopsis nuclear tRNAHis genes ubiquitously contain C54, as do those from tobacco, lupin and pea. The C54 nucleotide is maintained in the mature tRNAHis, which is aminoacylated in vivo , but to a relatively low level compared with other tRNAs examined. Finally, it was shown that an Arabidopsis tRNAHis gene with T54in place of C54 is over 5-fold more transcriptionally active than the wild-type gene using an in vitro system derived from plant nuclei. A possible role for this apparently sub-optimal tRNAHis sequence is suggested.