Functional role of the 5' terminal cloverleaf in Coxsackievirus RNA replication.
Using cell-free reactions, we investigated the role of the 5' cloverleaf (5'CL) and associated C-rich sequence in Coxsackievirus B3 RNA replication. We showed that the binding of poly(C) binding protein (PCBP) to the C-rich sequence was the primary determinant of RNA stability. In addition, inhibition of negative-strand synthesis was only observed when PCBP binding to both stem-loop 'b' and the C-rich sequence was inhibited. Taken together, these findings suggest that PCBP binding to the C-rich sequence was sufficient to support RNA stability and negative-strand synthesis. Mutational analysis of the three conserved structural elements in stem-loop 'd' showed that they were required for efficient negative- and positive-strand synthesis. Finally, we showed an RNA with a 5' terminal deletion (Delta49TD RNA), which was previously isolated from persistently infected cells, replicated at low but detectable levels in these reactions. Importantly, the critical replication elements identified in this study are still present in the Delta49TD RNA.
Sharma
Nidhi
N
Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
Ogram
Sushma A
SA
Morasco
B Joan
BJ
Spear
Allyn
A
Chapman
Nora M
NM
Flanegan
James B
JB
D004268:DNA-Binding Proteins; D004770:Enterovirus / Q000235:genetics / Q000502:physiology*; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000378:metabolism; D006801:Humans; D009154:Mutation; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D020871:RNA Stability; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D016601:RNA-Binding Proteins; D014779:Virus Replication
D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C094604:PCBP1 protein, human; D012367:RNA, Viral; D016601:RNA-Binding Proteins