Viral Replication

Question 1

which naked viruses are infectious

Answer 1

1. most dsDNA viruses
2. (+) strand ssRNA (SENSE strand)

Question 2

which naked viruses are non-infectious

Answer 2

1. dsRNA
2. (-) strand ssRNA (ANTI-sense strand)
   **these viruses MUST have a polymerase contained in the complete virion)

Question 3

all viral genomes must make mRNA that can be read by ?

Answer 3

mRNA that can be read by HOST RIBOSOMES (no exceptions)

Question 4

HIV Gag gene - overview

Answer 4

“group specific antigens”
*translated as a polyprotein
*key STRUCTURAL element of virion
*proteolyzed into 3 virion proteins

Question 5

HIV Gag gene - proteins encoded for

Answer 5

1. MA or matrix (membrane associated protein)
2. CA or capsid (forms capsid structure in mature virion)
3. NC or nucleocapsid protein (RNA-binding protein that assembles with genome)

Question 6

HIV Pol gene - overview

Answer 6

*polymerase
*encodes 3 proteins unique to retroviruses

Question 7

HIV Pol gene - proteins encoded for

Answer 7

1. RT or reverse transcriptase (multifunctional enzyme that transcribes RNA into DNA)
2. IN or integrase (catalyzes the integration of the viral DNA into the genome)
3. PR or protease (processes Pol and Gag polyproteins)

Question 8

HIV Env gene - overview

Answer 8

*envelope proteins
*env proteins insert into the host membrane and are acquired during budding

Question 9

HIV Env gene - proteins coded for

Answer 9

1. SU or surface protein (larger, primary viral attachment protein; gp120 in HIV)
2. TM or transmembrane protein (anchors SU to surface of viral membrane; gp41 in HIV)

Question 10

what class of viruses are the ONLY viruses that require INTEGRATION of the genome into the host DNA to replicate

Answer 10

RETROviruses (like HIV)