eEF1A binding to aminoacylated viral RNA represses minus strand synthesis by TYMV RNA-dependent RNA polymerase

• Published in: Virology (New York, N.Y.) Vol. 321; no. 1; pp. 47 - 56
• Main Authors: Matsuda, Daiki, Yoshinari, Shigeo, Dreher, Theo W
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 30-03-2004
• Subjects: Acylation; Minus strand synthesis; Nucleic Acid Conformation; Peptide Elongation Factor 1 - metabolism; Peptide Elongation Factor 1 - physiology; Positive-strand RNA virus; Protein Binding; Protein Biosynthesis; Replication; RNA Replicase - metabolism; RNA, Transfer - genetics; RNA, Transfer - metabolism; RNA, Viral - biosynthesis; RNA, Viral - genetics; RNA, Viral - metabolism; RNA-dependent RNA polymerase; Templates, Genetic; Translation; tRNA-like structure; Turnip yellow mosaic virus; Tymovirus - enzymology; Tymovirus - genetics; Replication; Translation; Positive-strand RNA virus; Turnip yellow mosaic virus; Minus strand synthesis; RNA-dependent RNA polymerase
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2003.10.028

The genomic RNA of
Turnip yellow mosaic virus (TYMV) has an 82-nucleotide-long tRNA-like structure at its 3′-end that can be valylated and then form a stable complex with translation elongation factor eEF1A·GTP. Transcription of this RNA by TYMV RNA-dependent RNA polymerase (RdRp) to yield minus strands has previously been shown to initiate within the 3′-CCA sequence. We have now demonstrated that minus strand synthesis is strongly repressed upon the binding of eEF1A·GTP to the valylated viral RNA. eEF1A·GTP had no effect on RNA synthesis templated by non-aminoacylated RNA. Higher eEF1A·GTP levels were needed to repress minus strand synthesis templated by valyl-EMV TLS RNA, which binds eEF1A·GTP with lower affinity than does valyl-TYMV RNA. Repression by eEF1A·GTP was also observed with a methionylated variant of TYMV RNA and with aminoacylated tRNA
His, tRNA
Ala, and tRNA
Phe transcripts. It is proposed that minus strand repression by eEF1A·GTP binding occurs early during infection to help coordinate the competing translation and replication functions of the genomic RNA.