Multiple repeating motifs are found in the 3'-terminal non-translated region of Semliki Forest virus A7 variant genome

• Published in: Journal of general virology Vol. 75; no. 6; pp. 1499 - 1504
• Main Authors: Santagati, Maria G, Itaranta, Petri V, Koskimies, Pasi R, Maatta, Jorma A, Salmi, Aimo A, Hinkkanen, Ari E
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.06.1994; Society for General Microbiology
• Subjects: Base Sequence; Biological and medical sciences; DNA Primers - chemistry; DNA, Complementary - genetics; Fundamental and applied biological sciences. Psychology; Genes, Viral; Genetics; Microbiology; Molecular Sequence Data; Repetitive Sequences, Nucleic Acid; RNA, Viral - genetics; Semliki Forest virus; Semliki forest virus - genetics; Semliki forest virus - pathogenicity; Sequence Alignment; Sequence Homology, Nucleic Acid; Viral Envelope Proteins - genetics; Viral Structural Proteins - genetics; Virology; Virus; Semliki forest virus; Genome organization; Nucleotide sequence; Repeated sequence; 3' terminal-Sequence; Non coding sequence; Togaviridae; Alphavirus; Glycoproteins; Virus envelope; Structural analysis
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-75-6-1499

Department of Virology, University of Turku, Kiinamyllynkatu 13, FIN-20520 Turku, Finland We have analysed the cDNA coding for the envelope glycoprotein (E1) gene and the terminal non-translated regions (NTRs) of the avirulent Semliki Forest virus (SFV) A774 (A7) variant. The E1 gene exhibited 98·5% identity to the SFV prototype strain L10 (WT) sequence at the nucleotide level. Of the 34 single base substitutions, six led to a change in the deduced amino acid sequence. The 3' NTR of A7 consisted of a 101 nucleotide sequence, not found in WT, followed by five tandemly arranged sequence motifs, two of which were truncated forms of the others. One full-length and one truncated repeat are found at the 3' NTR of WT. The repeats of A7 were followed by a non-repeating sequence, very similar to the equivalent region in WT. Owing to the unique sequence motif and the tandem repeats, the 3' NTR of A7 is 334 nucleotides longer than that of WT. Each of the repeats had an internal 12 nucleotide motif complementary to a conserved sequence in the 5'-terminal non-structural protein 1-encoding region, thought to be important in alphavirus RNA replication. In the 5' NTR, three point mutations were found. The conserved sequence binding to the repeated 3' motifs was identical in A7 and WT. Received 9 August 1993; accepted 13 December 1993.