Terminal structures of West Nile virus genomic RNA and their interactions with viral NS5 protein.
Genome cyclization is essential for flavivirus replication. We used RNases to probe the structures formed by the 5'-terminal 190 nucleotides and the 3'-terminal 111 nucleotides of the West Nile virus (WNV) genomic RNA. When analyzed individually, the two RNAs adopt stem-loop structures as predicted by the thermodynamic-folding program. However, when mixed together, the two RNAs form a duplex that is mediated through base-pairings of two sets of RNA elements (5'CS/3'CSI and 5'UAR/3'UAR). Formation of the RNA duplex facilitates a conformational change that leaves the 3'-terminal nucleotides of the genome (position -8 to -16) to be single-stranded. Viral NS5 binds specifically to the 5'-terminal stem-loop (SL1) of the genomic RNA. The 5'SL1 RNA structure is essential for WNV replication. The study has provided further evidence to suggest that flavivirus genome cyclization and NS5/5'SL1 RNA interaction facilitate NS5 binding to the 3' end of the genome for the initiation of viral minus-strand RNA synthesis.
Dong
Hongping
H
Wadsworth Center, New York State Department of Health, Albany, New York 12201, USA.
Zhang
Bo
B
Shi
Pei-Yong
PY
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D006224:Cricetinae; D016679:Genome, Viral / Q000235:genetics; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D023302:Protein Footprinting; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000378:metabolism*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014902:West Nile virus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
C096041:NS5 protein, flavivirus; D012367:RNA, Viral; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins