Reversible RNA phosphorylation stabilizes tRNA for cellular thermotolerance.
Reversible RNA phosphorylation stabilizes tRNA for cellular thermotolerance.
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DOI：
10.1038/s41586-022-04677-2
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发表时间：
2022-05
期刊：
影响因子：
64.8
通讯作者：
中科院分区：
文献类型：
--
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转录后修饰在tRNA的稳定性和功能中具有关键作用。在嗜热菌中，tRNA被大量修饰以在极端生长温度下保持其热稳定性。我们在嗜热古菌的tRNA的47位上鉴定了2′-磷酸尿苷（Up）。Up 47赋予tRNA热稳定性和核酸酶抗性。原生古细菌tRNA的原子结构显示出由Up 47稳定的独特亚稳态核心结构。Up 47的2′-磷酸从tRNA核心突出，并在热变性过程中阻止主链旋转。此外，我们还鉴定了arkI基因，该基因编码一种负责Up 47形成的古细菌RNA激酶。结构研究表明，ArkI有一个非典型的激酶基序周围的正电荷补丁的tRNA结合。敲除的arkI菌株在高温下生长缓慢，当第二种tRNA修饰酶耗尽时，表现出合成生长缺陷。我们还确定了一个古细菌同源KptA作为橡皮擦，有效地去磷酸化Up 47在体外和体内。总之，我们的研究结果表明，Up 47是一种可逆的RNA修饰，由ArkI和KptA介导，在极端环境条件下微调tRNA的结构刚性。可逆的内部RNA磷酸化有助于tRNA的热稳定性和核酸酶抗性，以及超嗜热菌的细胞耐热性。
Post-transcriptional modifications have critical roles in tRNA stability and function. In thermophiles, tRNAs are heavily modified to maintain their thermal stability under extreme growth temperatures. Here we identified 2′-phosphouridine (Up) at position 47 of tRNAs from thermophilic archaea. Up47 confers thermal stability and nuclease resistance to tRNAs. Atomic structures of native archaeal tRNA showed a unique metastable core structure stabilized by Up47. The 2′-phosphate of Up47 protrudes from the tRNA core and prevents backbone rotation during thermal denaturation. In addition, we identified the arkI gene, which encodes an archaeal RNA kinase responsible for Up47 formation. Structural studies showed that ArkI has a non-canonical kinase motif surrounded by a positively charged patch for tRNA binding. A knockout strain of arkI grew slowly at high temperatures and exhibited a synthetic growth defect when a second tRNA-modifying enzyme was depleted. We also identified an archaeal homologue of KptA as an eraser that efficiently dephosphorylates Up47 in vitro and in vivo. Taken together, our findings show that Up47 is a reversible RNA modification mediated by ArkI and KptA that fine-tunes the structural rigidity of tRNAs under extreme environmental conditions. Reversible internal RNA phosphrylation contributes to thermal stability and nuclease resistance of tRNA, and cellular thermotolerance of hyperthermophiles.
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影响因子：
2.9
作者：
HILBERS, CW;ROBILLARD, GT;RIESNER, D
通讯作者：
RIESNER, D
影响因子：
14.9
作者：
Dalluge, JJ;Hashizume, T;Davis, DR
通讯作者：
Davis, DR
影响因子：
14.9
作者：
Miyauchi, Kenjyo;Ohara, Tomoya;Suzuki, Tsutomu
通讯作者：
Suzuki, Tsutomu
影响因子：
2.9
作者：
Motorin, Yuri;Helm, Mark
通讯作者：
Helm, Mark
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH