Structural basis for Tpt1-catalyzed 2'-PO4 transfer from RNA and NADP(H) to NAD.
Structural basis for Tpt1-catalyzed 2'-PO4 transfer from RNA and NADP(H) to NAD.
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Tpt1 催化 2-PO4 从 RNA 和 NADP(H) 转移到 NAD 的结构基础。
DOI：
10.1073/pnas.2312999120
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发表时间：
2023
影响因子：
11.1
通讯作者：
Shuman,Stewart
中科院分区：
文献类型：
--
作者：
Jacewicz,Agata;Dantuluri,Swathi;Shuman,Stewart
Tpt1是真菌和植物tRNA剪接的重要试剂，它可以去除tRNA连接酶产生的内部RNA2‘-磷酸。Tpt1还去除了由Ark1激酶安装在古生菌tRNA的V-环中的2‘-磷酸尿苷标记。Tpt1进行两步反应，其中2‘-PO4攻击NAD+形成RNA-2’-磷酸-(ADP-核糖)中间体，ADP-核糖O2“的酯交换反应生成RNA2‘-OHRNA和ADP-核糖-1”，2“-环磷酸。在这里，我们介绍了古生菌Tpt1酶的结构，它们是与ADP-核糖-1“-PO4、ADP-核糖-2”-PO4和2‘-OH RNA的产物络合物，以及与2’，5‘-ADP和NAD+的底物络合物，揭示了2’-PO4连接的识别和催化。我们发现古生菌Tpt1酶可以利用含有2‘-PO4的代谢物NADP+和NADPH作为底物将2’-PO4转移到NAD+。Tpt1在2‘-磷酸-NADP(H)动力学中的作用为Tpt1在缺乏内部RNA2’-磷酸化能力的分类群中的流行提供了理论基础。
Tpt1 is an essential agent of fungal and plant tRNA splicing that removes an internal RNA 2′-phosphate generated by tRNA ligase. Tpt1 also removes the 2′-phosphouridine mark installed by Ark1 kinase in the V-loop of archaeal tRNAs. Tpt1 performs a two-step reaction in which the 2′-PO4attacks NAD+to form an RNA-2′-phospho-(ADP-ribose) intermediate, and transesterification of the ADP-ribose O2″ to the RNA 2′-phosphodiester yields 2′-OH RNA and ADP-ribose-1″,2″-cyclic phosphate. Here, we present structures of archaeal Tpt1 enzymes, captured as product complexes with ADP-ribose-1″-PO4, ADP-ribose-2″-PO4, and 2′-OH RNA, and as substrate complexes with 2′,5′-ADP and NAD+, that illuminate 2′-PO4junction recognition and catalysis. We show that archaeal Tpt1 enzymes can use the 2′-PO4-containing metabolites NADP+and NADPH as substrates for 2′-PO4transfer to NAD+. A role in 2′-phospho-NADP(H) dynamics provides a rationale for the prevalence of Tpt1 in taxa that lack a capacity for internal RNA 2′-phosphorylation.