STEP THIRTEEN: Polio Summary 1. Humans & chimps; 2. Picorna, Entero; 3. SMALL, ~30 nm 4. CD155; 5. 2 proteases, 4 structural proteins, polymerase 9. 3 serotypes; 10. Gut (GALT); 11. Eradicated in Western countries 13. 90% Asymptomatic; flu-like; muscle spasm; paralytic myelitis 0.1-2% > fatal or residual paralysis; PPS > slow complication, 30-40y later 14. IPV > formaline-fixed; suitable for immuno-compromised people OPV > live vaccine; can cause 2 nd ry infection from feces (VAPP) *Numbers correspond to those of the “Summary Table” from the website Replication VPg – 20-24 AA; hydroPHOBIC; linked to tyrosine OH at RNA 5’ end > stick to cell membrane, VPg-Poly-U grabs Poly-A of mRNAs > need to be cleaved for translation; cap-independent translation IRES – internal stem-loop RNA structure at 5’ end; ribosome binding site Poly-A – 3’ end of RNA; REPLICATED into POLY-U Polymerase – becomes functional when combined w/ one cellular protein Replication is entirely cytoplasmic
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