MICRB 201 Study Guide - Final Guide: Keratinocyte, Foodborne Illness, Wicket-Keeper
Document Summary
Very similar to : adsorbtion, host range and tissue specificity, depends on interaction between host cell receptor (has a normal physiological function) and viral surface protein, penetration and uncoating, variable mechanisms depending on type of virus (fig. Some viruses use host enzymes; others use virus-encoded enzymes. Generally involves use of host rna polymerases. Strategy depends on nature of genome: positive single stranded (ss) (fig 6. 25): genome acts as mrna, negative single stranded: use of virus-encoded rna dependent rna pol. (aka. Transcriptase) to convert genome to mrna template (fig 11. 20: double-stranded (ds): some also use a transcriptase. Retro because transcription and replication requires conversion of rna genome to. Many retroviruses kill their host, very damaging. Key enzyme: reverse transcriptase (rt) converts rna to dna. 1: + ssrna (via rt) dna/rna hybrid. *activity of rt as an rna-dependent dna pol: dna/rna hybrid (via rt) -ss dna. *activity of rt as a ribonuclease h (degrades rna of dna/rna hybrids) c)
