Introduction of the 3Dpol mutation to RDRP and movement of the Cre5 cis-acting replication element reduced the risk of reversion in a vaccine against this virus. For 10 points each:
[10e] Name this paralysis-inducing virus whose heat-killed vaccine was invented by Jonas Salk.
ANSWER: poliovirus
[10m] The poliovirus genome exists in this form while in the viral particle. Viruses in Baltimore class 4 have this type of genome, which can replicate its own RNA [emphasize] without packaging RNA-dependent RNA polymerase in the virion.
ANSWER: positive-sense single-stranded RNA [or +ssRNA; accept plus-sense single-stranded RNA; prompt on RNA or single stranded RNA]
[10h] Due to their lack of a 5-prime cap, polioviruses use these 5-prime UTR-localized sequences to recruit ribosomes. These RNA elements form secondary structures in the viral genome and bind to initiation factors to initiate translation.
ANSWER: internal ribosome entry sites [or IRESs]
<Shahar Schwartz, Biology>