Plant tRNA ligases are multifunctional enzymes that have diverged in sequence and substrate specificity from RNA ligases of other phylogenetic origins.
Plant tRNA ligases are multifunctional enzymes that have diverged in sequence and substrate specificity from RNA ligases of other phylogenetic origins.
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DOI：
10.1093/nar/gki174
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发表时间：
2005
影响因子：
14.9
通讯作者：
Beier H
中科院分区：
文献类型：
--
作者：
Englert M;Beier H
前体tRNA剪接是所有真核生物中必不可少的过程。它需要核酸内切酶的协同作用来去除内含子，并需要连接酶来连接所得的tRNA半体，如在酵母酿酒酵母中研究得最好的。在这里，我们报告的RNA连接酶蛋白质和它的基因从一个更高的真核生物，是前tRNA剪接过程中的一个重要组成部分的第一个特征。通过连续的柱层析步骤从小麦胚芽中纯化tRNA连接酶，通过其共价结合AMP的潜力，以及通过其催化tRNA半体的连接和线性内含子的环化的能力，鉴定出125 kDa的蛋白质。从纯化的蛋白质中获得的肽序列导致在拟南芥和稻属数据库中的相应蛋白质及其基因的阐明。植物tRNA连接酶与任何已知的RNA连接酶没有整体序列同源性，然而，它们具有许多保守的基序，表明存在三种内在酶活性：N-末端区域的腺苷酰转移酶/连接酶结构域，中心的多核苷酸激酶和C-末端的环状磷酸二酯酶结构域。在体外表达的重组拟南芥tRNA连接酶和功能分析显示所有预期的个人活动。植物RNA连接酶在体外对多种底物具有活性，并且能够进行分子间和分子内RNA连接。因此，我们得出结论，他们在体内的作用可能包括尚未未知的基本功能，除了他们参与前tRNA剪接。
Pre-tRNA splicing is an essential process in all eukaryotes. It requires the concerted action of an endonuclease to remove the intron and a ligase for joining the resulting tRNA halves as studied best in the yeast Saccharomyces cerevisiae. Here, we report the first characterization of an RNA ligase protein and its gene from a higher eukaryotic organism that is an essential component of the pre-tRNA splicing process. Purification of tRNA ligase from wheat germ by successive column chromatographic steps has identified a protein of 125 kDa by its potentiality to covalently bind AMP, and by its ability to catalyse the ligation of tRNA halves and the circularization of linear introns. Peptide sequences obtained from the purified protein led to the elucidation of the corresponding proteins and their genes in Arabidopsis and Oryza databases. The plant tRNA ligases exhibit no overall sequence homologies to any known RNA ligases, however, they harbour a number of conserved motifs that indicate the presence of three intrinsic enzyme activities: an adenylyltransferase/ligase domain in the N-terminal region, a polynucleotide kinase in the centre and a cyclic phosphodiesterase domain at the C-terminal end. In vitro expression of the recombinant Arabidopsis tRNA ligase and functional analyses revealed all expected individual activities. Plant RNA ligases are active on a variety of substrates in vitro and are capable of inter- and intramolecular RNA joining. Hence, we conclude that their role in vivo might comprise yet unknown essential functions besides their involvement in pre-tRNA splicing.
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DOI：
10.1073/pnas.74.12.5453
发表时间：
1977-01-01
影响因子：
11.1
作者：
GOODMAN, HM;OLSON, MV;HALL, BD
通讯作者：
HALL, BD
影响因子：
2.9
作者：
CAMERON, V;UHLENBECK, OC
通讯作者：
UHLENBECK, OC
影响因子：
5.1
作者：
Akama, K;Junker, V;Beier, H
通讯作者：
Beier, H
影响因子：
11.4
作者：
AMITSUR, M;LEVITZ, R;KAUFMANN, G
通讯作者：
KAUFMANN, G
DOI：
10.1073/pnas.0401090101
发表时间：
2004-04-27
影响因子：
11.1
作者：
Daròs, JA;Flores, R
通讯作者：
Flores, R