Department of Biological Sciences, State University of New York, Buffalo, NY, 14260, United States of America.
Human Biology Program, School of Integrative and Global Majors, University of Tsukuba, Ibaraki, 305-8575, Japan.
Sci Rep. 2017 Sep 14;7(1):11662. doi: 10.1038/s41598-017-11693-0.
Methanothermobacter thermoautotrophicus RNA ligase (MthRnl) catalyzes formation of phosphodiester bonds between the 5'-phosphate and 3'-hydroxyl termini of single-stranded RNAs. It can also react with RNA with a 3'-phosphate end to generate a 2',3'-cyclic phosphate. Here, we show that MthRnl can additionally remove adenosine from the 3'-terminus of the RNA to produce 3'-deadenylated RNA, RNA(3'-rA). This 3'-deadenylation activity is metal-dependent and requires a 2'-hydroxyl at both the terminal adenosine and the penultimate nucleoside. Residues that contact the ATP/AMP in the MthRnl crystal structures are essential for the 3'-deadenylation activity, suggesting that 3'-adenosine may occupy the ATP-binding pocket. The 3'-end of cleaved RNA(3'-rA) consists of 2',3'-cyclic phosphate which protects RNA(3'-rA) from ligation and further deadenylation. These findings suggest that ATP-dependent RNA ligase may act on a specific set of 3'-adenylated RNAs to regulate their processing and downstream biological events.
产甲烷热原体 RNA 连接酶（MthRnl）催化单链 RNA 5'-磷酸和 3'-羟基末端之间磷酸二酯键的形成。它还可以与具有 3'-磷酸末端的 RNA 反应，生成 2'，3'-环磷酸。在这里，我们表明 MthRnl 还可以从 RNA 的 3'-末端去除腺苷，产生 3'-去腺苷化 RNA，RNA(3'-rA)。这种 3'-去腺苷化活性依赖于金属，并且需要末端腺苷和倒数第二个核苷都具有 2'-羟基。与 MthRnl 晶体结构中的 ATP/AMP 接触的残基对于 3'-去腺苷化活性是必需的，这表明 3'-腺苷可能占据 ATP 结合口袋。切割的 RNA(3'-rA)的 3'-末端由 2'，3'-环磷酸组成，这保护 RNA(3'-rA)免受连接和进一步去腺苷化。这些发现表明，ATP 依赖性 RNA 连接酶可能作用于一组特定的 3'-腺苷化 RNA，以调节它们的加工和下游生物学事件。
