Chapter 6. Picornaviruses - Part II Assume that the strand below is the poliovirus RNA genome. Write out the sequence of the (-) RNA strand, and then the sequence of the new (+) RNA strands that would be made for the progeny virus. For now, ignore the VPg molecule at the end of the RNA - instead, focus on the nucleotide sequence and strand polarity. Genome: 5'(VPg-U-U)- A C GA UU AG CUA A GG CGUG CCGCGCUAUAAUAAA - 3' (-) RNA: – – (+) RNA: – – (for progeny) Is there a DNA component in the replication cycle? What enzyme copies the (+) RNA template and where does it come from?
Fill in the key events of a poliovirus replication cycle. parental virion 9 viral RNA progeny virions 3 polyprotein 4 non-strucural proteins structural proteins replication complex 1. 2. 3. 4. 5. 6. 7. 8. 9.
What proteins would be needed right away in the replication compartment? What is the dashed line in the replication compartment? How does poliovirus ensure that it packages a copy of its (+) RNA and not the (-) RNA or the cell's mRNA? What is the big "blob" on the RNA in the replication compartment and what exactly is it doing? What happens inside the capsid that results in the virus maturing and becoming an infectious particle? Write out the identities of the viral proteins in the capsid of an immature, non-infectious poliovirus. How many protein molecules are there in the capsid? Write out the identities of the viral proteins in the capsid of a mature, infectious poliovirus. How many protein molecules are there in the capsid?