Virus‐specific capping of tobacco mosaic virus RNA: methylation of GTP prior to formation of covalent complex p126‐m7GMP

FEBS Letters

Ahola, Tero¹  Kääriäinen, Leevi¹  Merits, Andres¹  Kettunen, Reetta¹  Auvinen, Petri¹  Lampio, Anja¹  Mäkinen, Kristiina¹ 

[1] Institute of Biotechnology, Biocenter Viikki, P.O. Box 56 (Viikinkaari 9), FIN-00014 University of Helsinki, Helsinki, Finland

关键词: Plant virus;    RNA replication;    Guanylyltransferase;    Methyltransferase;    Tobacco mosaic virus;   

DOI  :  10.1016/S0014-5793(99)00856-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In capping cellular mRNAs, a covalent GMP-enzyme intermediate leads to formation of G(5′)ppp(5′)N at the 5′ end of the RNA, which is modified by methylation catalyzed by guanine-7-methyltransferase. Here we show that isolated membranes from tobacco mosaic virus (TMV)-infected plant or insect cells expressing TMV replicase protein p126, synthesized m⁷GTP using S-adenosylmethionine (AdoMet) as the methyl donor, and catalyzed the formation of a covalent guanylate-p126 complex in the presence of AdoMet. The methyl group from AdoMet was incorporated into p126, suggesting that the complex consisted of m⁷GMP-p126. Thus, TMV and alphaviruses, despite their evolutionary distance, share the same virus-specific capping mechanism.

【 授权许可】

Unknown