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-Structure paper
タイトル | Identification of the active sites in the methyltransferases of a transcribing dsRNA virus. |
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ジャーナル・号・ページ | J Mol Biol, Vol. 426, Issue 11, Page 2167-2174, Year 2014 |
掲載日 | 2014年5月29日 |
著者 | Bin Zhu / Chongwen Yang / Hongrong Liu / Lingpeng Cheng / Feng Song / Songjun Zeng / Xiaojun Huang / Gang Ji / Ping Zhu / |
PubMed 要旨 | Many double-stranded RNA (dsRNA) viruses are capable of transcribing and capping RNA within a stable icosahedral viral capsid. The turret of turreted dsRNA viruses belonging to the family Reoviridae ...Many double-stranded RNA (dsRNA) viruses are capable of transcribing and capping RNA within a stable icosahedral viral capsid. The turret of turreted dsRNA viruses belonging to the family Reoviridae is formed by five copies of the turret protein, which contains domains with both 7-N-methyltransferase and 2'-O-methyltransferase activities, and serves to catalyze the methylation reactions during RNA capping. Cypovirus of the family Reoviridae provides a good model system for studying the methylation reactions in dsRNA viruses. Here, we present the structure of a transcribing cypovirus to a resolution of ~3.8Å by cryo-electron microscopy. The binding sites for both S-adenosyl-L-methionine and RNA in the two methyltransferases of the turret were identified. Structural analysis of the turret in complex with RNA revealed a pathway through which the RNA molecule reaches the active sites of the two methyltransferases before it is released into the cytoplasm. The pathway shows that RNA capping reactions occur in the active sites of different turret protein monomers, suggesting that RNA capping requires concerted efforts by at least three turret protein monomers. Thus, the turret structure provides novel insights into the precise mechanisms of RNA methylation. |
リンク | J Mol Biol / PubMed:24690366 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.8 Å |
構造データ | |
化合物 | ChemComp-SAH: |
由来 |
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キーワード | VIRUS / dsRNA virus / Reoviridae / RNA capping / RNA methyltransferase |