BIO % % exam

vif; APOBECC3F and G

HUman hiv protein excudes the -= from packaging into progeny

class v11- dsdna viruses with an rna intermediate

since these viruses did not fall into any of the known classes, their disocvery led to the following new class in virus classification system

true/t

t/f human HBV genome in virion capsid is partly ssdna and partly dsdna

c

7) Which one of the following statements about human hepadnaviruses is not true?
a) hepatitis B virus belongs in this group
b) these viruses use reverse transcription although they have a DNA genome
c) the genome inside the virion is cccDNA
d) these viruses belong in the Baltimore class VII
e) these viruses have roughly spherical capsids

viruses are remnants of cellular organisms

the regressive or reduction hypothesis about virus origins states that

progressive or escapy hypothesis

The process described in the __________________________ about virus origins very closely mirrors the
movement of a component of most eukaryotic genomes: retrotransposons.

virus in a new host

nipah virus in pigs and humans is an example of

new virus (newly evolved virus)

influenza virus reassortants is an example of

flying fox fruit bats

hendravirus natural reservoir seems to be a

5 million

How many new HIV infections occur annually?

4th

What is HIV's rank in global mortality?

cone

What is the shape of the HIV capsid?

NC protein

Which HIV protein contains zinc fingers?

gp41 gp120

Which HIV glycoproteins are TM and SU?

MA

Which HIV protein binds gp41 C-terminus inside virion?

gp41 gp120 trimer

What forms HIV surface spikes?

HIV1 HIV2

What are the two types of HIV?

SIV

What virus did HIV evolve from?

late 20th

When did HIV emerge?

no

Do SIVs harm their natural hosts?

HIV1

Which HIV type is most prevalent?

HIV1

Which HIV type caused the pandemic?

West Africa

Where is HIV2 mainly found?

aux genes

What extra genes does HIV1 encode?

complex retrovirus

What type of retrovirus is HIV1?

3

How many reading frames does HIV1 use?

overlap

What is unique about HIV genome organization?

tRNA

What primes HIV reverse transcriptase?

microtubules

What does HIV RT complex associate with?

CD4

What receptor does HIV bind on host cells?

T helper cells

What cells are primary HIV targets?

gp120 CD4

How does HIV attach to host cells?

co-receptor

What additional receptor is required for HIV entry?

CCR5 CXCR4

Which co-receptors does HIV1 use?

CCR5 deletion

What mutation provides HIV resistance?

no CCR5

How does CCR5 mutation protect against HIV?

Europeans

Where is CCR5 mutation most common?

gp41 rearrangement

What occurs after gp120 binds CD4 and co-receptor?

membrane fusion

What does gp41 rearrangement cause?

cytoplasm entry

Where do HIV contents go after fusion?

RT complex

What forms after HIV enters the cell?

NF-kB

Which TF is key for HIV transcription?

AP1 SP1

Which TFs also bind HIV LTR?

downstream LTR

Where does HIV transcription terminate?

R region

Where is HIV polyA signal?

polyadenylation

What modification do HIV transcripts undergo?

splicing

What happens to HIV RNA transcripts?

9.3 4.5 2 kb

What sizes are HIV transcripts?

30 mRNA

How many HIV mRNAs are produced?

Nef Tat Rev

Which HIV proteins are early?

frameshifting

How is HIV gag-pol produced?

replication boost

What is Nef’s true function?

decrease CD4 MHC

How does Nef evade immunity?

endosome trafficking

How does Nef act in cells?

TAR RNA

Where does HIV Tat bind?

RNA pol II kinase

How does Tat enhance transcription?

processivity

What does Tat increase?

RRE

Where does HIV Rev bind?

early to late

What shift does Rev cause?

blocks APOBEC

What is Vif’s main function?

APOBEC proteins

What host enzymes does Vif target?

C→U mutation

How do APOBEC proteins act?

Vif mutation

What happens if Vif is defective?

RT stage

When do APOBECs act?

CCR5→CXCR4

What co-receptor shift occurs in HIV progression?

asymptomatic

When do X4 strains appear?

faster AIDS

What does early X4 emergence cause?

10^10/day

How many HIV virions are produced daily?

CD4 death

Why is immunity impaired in HIV?

antigen variation

How does HIV escape antibodies?

latency

Why can HIV persist long-term?

blood screening

How is HIV spread prevented in transfusions?

auto syringes

How do syringes reduce HIV spread?

15–40%

What is HIV mother-to-child transmission risk?

breastfeeding

How else can HIV be transmitted to infants?

antivirals

How is vertical HIV transmission reduced?

PEP

What prevents HIV after exposure?

high mutation

Why is HIV vaccine difficult?

integrase inhibitor

What class is elvitegravir?

integration block

How does elvitegravir work?

CYP3A inhibitor

What is cobicistat’s function?

booster

What is cobicistat’s role?

cytidine analog

What type of drug is emtricitabine?

fluorine

What is unique about emtricitabine?

prodrug

What is tenofovir DF?

AMP analog

What type is tenofovir?

RT inhibition

How do emtricitabine and tenofovir work?

hepadnavirus

What family is HBV in?

RNA intermediate

Why is HBV unusual?

class VII

What Baltimore class is HBV?

pararetrovirus

What group is HBV in?

42 nm

What is HBV virion size?

envelope capsid

What is HBV structure?

DNA + P

What is inside HBV capsid?

partial dsDNA

What type is HBV genome?

incomplete strand

Why is HBV DNA partial?

5' overlap

What creates HBV triple strand region?

3.2 kb

What is HBV genome size?

RNA + P

What is attached to HBV DNA ends?

RT RNase H

What domains does HBV polymerase have?