Biogenesis of 2-agmatinylcytidine catalyzed by the dual protein and RNA kinase TiaS
Biogenesis of 2-agmatinylcytidine catalyzed by the dual protein and RNA kinase TiaS
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DOI：
10.1038/nsmb.2121
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发表时间：
2011-11
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影响因子：
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通讯作者：
Naohiro Terasaka;S. Kimura;T. Osawa;T. Numata;Tsutomu Suzuki
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文献类型：
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作者：
Naohiro Terasaka;S. Kimura;T. Osawa;T. Numata;Tsutomu Suzuki
古细菌AUA密码子特异性tRNA I在反密码子摆动位置（位置34）含有2-胍基胞嘧啶（agm 2C或agmatidine）。这种必需的修饰的形成由tRNAIle-agm 2C合成酶（TiaS）使用胍丁胺和ATP作为底物催化。TiaS有一个以前未知的催化结构域，我们将其命名为Thr 18-Cyt 34激酶结构域（TCKD）。对闪烁古生球菌TiaS及其突变体的生化分析表明，TCKD首先将ATP水解为AMP和焦磷酸，然后用γ-磷酸将C34的C2位磷酸化。接下来，胍丁胺的氨基攻击该位置以释放磷酸并形成agm 2C。值得注意的是，TCKD还使TiaS的Thr 18自磷酸化，这可能参与agm 2C的形成。因此，TiaS的独特激酶结构域催化蛋白质和RNA底物的双重磷酸化。
The archaeal AUA-codon specific tRNAIlecontains 2-agmatinylcytidine (agm2C or agmatidine) at the anticodon wobble position (position 34). The formation of this essential modification is catalyzed by tRNAIle-agm2C synthetase (TiaS) using agmatine and ATP as substrates. TiaS has a previously unknown catalytic domain, which we have named the Thr18-Cyt34 kinase domain (TCKD). Biochemical analyses ofArchaeoglobus fulgidusTiaS and its mutants revealed that the TCKD first hydrolyzes ATP into AMP and pyrophosphate, then phosphorylates the C2 position of C34 with the γ-phosphate. Next, the amino group of agmatine attacks this position to release the phosphate and form agm2C. Notably, the TCKD also autophosphorylates the Thr18 of TiaS, which may be involved in agm2C formation. Thus, the unique kinase domain of TiaS catalyzes dual phosphorylation of protein and RNA substrates.