DNA Viruses (6) Flashcards
What do Rep78/68 do?
a. Allow for adenovirus to colonise the respiratory tract
b. Nick ds Parvovirus DNA to define the end of the genome
c. Bind to Parvovirus ITR to prime the ssDNA for replication
d. Prevent splicing of Poxvirus RNA
b. Nick ds Parvovirus DNA to define the end of the genome
What allows Poxvirus to replicate its genome in the cytoplasm?
a. The genome encodes extensive RNA splicing machinery that produces many different sized transcripts in the cytoplasm
b. It manipulates host RNA pol and DNA pol before entering the nucleus
c. Replication produces an immediate early T-protein which binds viral DNA and allows cytoplasmic replication
d. The virus encodes viral RNA pol, capping enzyme, polyA pol and DNA pol
d. The virus encodes viral RNA pol, capping enzyme, polyA pol and DNA pol
Which is a Baltimore class II virus? What does this mean?
a. Parvovirus. ssDNA is converted to +mRNA via a dsDNA intermediate
b. Adenovirus. Circular DNA can directly integrate into host DNA
c. Poxvirus. DNA is replicated in the cytoplasm
d. Herpesvirus. +ssRNA is duplicated to form dsDNA that can integrate into a host genome
a. Parvovirus. ssDNA is converted to +mRNA via a dsDNA intermediate
Which is correct?
a. Splicing occurs in Poxviridae and Hepadnaviridae
b. Only hepadnaviridae possess their own transciptase
c. Parvoviridae use cellular transcriptase and RNA is spliced
d. A viral reverse trancriptase is present in Papovaviridae
c. Parvoviridae use cellular transcriptase and RNA is spliced
What doesn’t constitute the Hepatitis B virus genome?
a. 3kb dsDNA
b. Viral polymerase
c. Four 12bp direct repeats
d. Capped RNA primer
c. Four 12bp direct repeats
• The Inverted Terminal Repeat on Parvovirus DNA is the primer and template for dsDNA synthesis.
T
• Poxvirus RNA can be spliced in the cytoplasm.
F
• Adenovirus, Parvovirus and Poxvirus all use DNA hairpin primers to replicate their DNA via strand displacement.
F
• As well as double walled virus particles, Hepatitis B virus has complete particles consisting of envelope proteins.
T
• There are four termination sequences in Hepatitis B mRNA.
F
What kind of viruses can directly fit into the flow of cell genetic information and can use cell enzymes?
a. dsDNA virsues and ss +RNA genome viruses
b. ss-RNA viruses
c. ss-RNA viruses and ss+ RNA viruses
d. ssDNA viruses and ds linear DNA viruses
a. dsDNA virsues and ss +RNA genome viruses
What is involved in cellular transcription?
a. RNA pol II binds downstream of the promoter
b. Transcription initiation factors bind the core promoter or enhancer sequences
c. RNA pol II is recruited directly by the enhancer
d. mRNA is synthesised from a DNA template using dNTPs
b. Transcription initiation factors bind the core promoter or enhancer sequences
What is false about transcriptional regulation in Papovavirus SV40?
a. VP2 and VP3 genes overlap and share some AAs due to being in the same reading frame
b. Early genes are transcribed in a counter clockwise direction and late genes are transcribed in a clockwise direction
c. Early promoters are recognised by host cell RNA transcription factors
d. The large T protein is produced following transcription of late genes
d. The large T protein is produced following transcription of late genes
Which DNA viruses carry their own polymerase?
a. Adenovirus and Papovavirus
b. Poxvirus and Herpesvirus
c. Adenovirus and Herpesvirus
d. Hepadnavirus and Poxvirus
d. Hepadnavirus and Poxvirus
What is not a function of the large T protein in Papovavirus SV40?
a. It initiates clockwise transcription and the activation of late viral genes
b. It suppresses DNA replication
c. It removes cellular proteins from DNA that repress transcription from the late promoter (antirepression)
d. It binds near the ori and unwinds Sv40 DNA
b. It suppresses DNA replication