1. http://www.virology.ws
VIRAL STRUCTURE & CLASSIFICATION
S144 Lecture 2 (Virology)
Marilen M. Parungao-Balolong
Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
2. SKILLS, VALUES, OUTPUTS
✤ Listening, Writing and
Oral Communication winfoin.com
Skills
✤ Critical Analysis and
Organization of Ideas
✤ Appreciate Importance
of Viral Structure
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
3. LECTURE OUTLINE
✤ Recall: Viruses
Introduction
✤ Structure of Viruses
✤ Functional Anatomy
✤ Classification
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
4. REFERENCES
✤ Carter and Saunders, 2007 (Chapter 3)
✤ Gelderblom, 2010 (Chapter 41)
✤ (Bookshelf ID: NBK8174 PMID: 21413309)
✤ http://www.ncbi.nlm.nih.gov/books/NBK8174/
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
5. LECTURE OUTLINE
✤ Recall: Viruses
Introduction
✤ Structure of Viruses
✤ Functional Anatomy
✤ Classification
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
6. VIRUSES: INTRODUCTION
✤ Viruses are small
obligate intracellular
parasites
✤ Contain either a
RNA or DNA
genome surrounded
by a protective,
virus-coded protein
coat
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
7. VIRUSES: INTRODUCTION
✤ Viruses may be viewed as mobile genetic elements, most probably of
cellular origin and characterized by a long co-evolution of virus and
host
bio3400.nicerweb.net
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
8. VIRUS: INTRODUCTION
✤ Propagation
depend on
specialized host
cells supplying
the complex
metabolic and
biosynthetic
machinery of
eukaryotic or ncbi.nlm.nih.gov
prokaryotic cells
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
9. LECTURE OUTLINE
✤ Recall: Viruses
Introduction
✤ Structure of Viruses virology.ws
✤ Functional Anatomy
✤ Classification
medical-dictionary.thefreedictionary.com
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
10. Reference: Chapter 3 Carter And Saunders, 2007)
Marilen M. Parungao-Balolong 2011 dvm5.blogspot.com
Thursday, June 30, 2011
11. CORONAVIRUS STRUCTURE:
SARS
http://learn.genetics.utah.edu/archive/sars/index.html
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
14. CHEMICAL COMPOSITION OF
GENOME
✤ The genome of a virus may consist of DNA or RNA,
which may be single stranded (ss) or double stranded
(ds), linear or circular
✤ The entire genome may occupy either one nucleic acid
molecule (monopartite genome) or several nucleic acid
segments (multipartite genome)
✤ The different types of genome necessitate different
replication strategies
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
15. INTRODUCTION TO VIRUS
STRUCTURE
✤ TYPES OF VIRION STRUCTURE
TYPES GENOMES
dsDNA ssDNA dsRNA ssRNA
Icosahedral
(naked)
Icosahedral
(Enveloped)
Helical (naked)
Helical
(Enveloped)
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
17. VIRUS GENOMES
✤ dsDNA
✤ encode their genes in the same kind of
molecule as animals, plants, bacteria and
other cellular organisms
✤ ssDNA, dsRNA, ssRNA
✤ unique to viruses
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
18. ARRANGEMENT OF GENOME
GENOME EXAMPLE
ssDNA, linear Parvovirus
dsDNA, linear Poxvirus
ssDNA, circular Phage X174
dsDNA, circular Baculoviruses
ssRNA, linear Tobacco Mosaic Virus
dsRNA, linear Reovirus
ssRNA, circular Hepatitis D virus
Note: there are no viruses known with circular dsRNA genomes
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
19. USUALLY....
✤ FUNGI VIRUSES
✤ dsRNA sdnhm.org
topnews.in
✤ PLANT VIRUSES http://
www.whmsoft.net
✤ ssRNA
✤ PROKARYOTIC VIRUSES
✤ dsDNA
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
20. POINTS TO REMEMBER...
✤ Some linear molecules may be in a
circular conformation as a result of base
pairing between complimentary
sequences at their ends
✤ Example:
✤ DNA in Hepadnavirus
✤ RNA in Influenza virions
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
21. THE CAPSID: PROTEIN CORE
virology.ws medical-dictionary.thefreedictionary.com
Take note of the nucleocapsid and envelope
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
22. THE CAPSID: PROTEIN CORE
Structure of adenovirus. The icosahedral capsid structure of
adenovirus is made up of three proteins, hexon, penton
base, and fiber. A cross-sectional view of the viral capsid.
Some proteins are associated with viral DNA, whereas
others are associated with hexon and are involved in the
formation of the capsid.
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
24. MORPHOLOGY : Helical
✤ In the replication of viruses
with helical symmetry,
identical protein subunits
(protomers) self-assemble
into a helical array
surrounding the nucleic
acid, which follows a
similar spiral path
✤ Nucleocapsids form rigid,
highly elongated rods or
flexible filaments
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
26. MORPHOLOGY
✤ Icosahedral
morphology is
characteristic of
the
nucleocapsids of
many
“spherical”
viruses
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
30. pc.maricopa.edu
THE CAPSOMERES
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
31. CAPSOMERES & ENVELOPE
✤ The number and
arrangement of the
capsomeres are useful
in identification and
classification
✤ Many viruses also
have an outer Envelope of
envelope Herpesvirus
biologie.uni-hamburg.de
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
32. CAPSID & ENVELOPE
pc.maricopa.edu
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
33. ✤ Envelope consists of a
lipid bilayer with proteins
(usually glycoproteins)
imbedded in it THE ENVELOPE
✤ Lipids derived from
host cell
✤ Proteins encoded by the
virus
✤ Envelope is important in
determining host cell
specificity & some aspects
of cell penetration are
affected by it
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
34. ENVELOPED VIRUSES
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
35. COMPLEX VIRUSES
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
36. LECTURE OUTLINE
✤ Recall: Viruses
Introduction
✤ Structure of Viruses
✤ Functional Anatomy
bbc.co.uk
✤ Classification
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
37. STRUCTURE IN RELATION TO
FUNCTION
✤ Core
! ! ! a.! DNA or RNA
! ! ! b.! Contains genetic
information
ncbi.nlm.nih.gov
!!
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
38. STRUCTURE IN RELATION TO
FUNCTION sparknotes.com
✤ Capsid
! ! ! a.! Outer protein coat
! ! ! b.! Functions
! ! ! ! 1).!Protects core
! ! ! ! 2).!Shape of the virus
! ! ! ! 3).!Attachment to host
cell membrane (by means of
spikes) library.thinkquest.org
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
39. STRUCTURE IN RELATION TO
FUNCTION
✤ Envelope
✤ Membrane around capsid - enveloped virus
✤ Not all viruses have envelope
✤ If lack envelope - naked virus!
✤ Composed of:
✤ Bilayer of phospholipids and proteins microscopicblog.blogspot.com
✤ Derived from host bell membrane during viral multiplication
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
40. STRUCTURE IN RELATION TO
FUNCTION me-you-and-virus.blogspot.com
wpro.who.int
✤ Functions :
✤ Protection from drying (enhances
transmission)
✤ Makes virus more susceptible to
chemical agents that dissolve lipids
✤ Attachment to host cell membrane
(by means of spikes)
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
41. LECTURE OUTLINE
✤ Recall: Viruses
Introduction
✤ Structure of Viruses
✤ Functional Anatomy
✤ Classification
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
42. ✤ Viruses are grouped on the basis of size and shape, chemical
composition and structure of the genome, and mode of replication
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
43. PLANT VIRUSES
Marilen M. Parungao-Balolong 2011 Reference: Chapter 13 TortoraMicrobiology
Thursday, June 30, 2011
44. CLASSIFYING ENVELOPED
VIRUS BASED ON SHAPE...
✤ Sphere (eg. Influenza
virus)
✤ Bullet (e.g. Rabies
virus)
✤ Rod (e.g. Baculovirus)
✤ Thread (e.g Ebola
virus)
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
45. CLASSIFYING VIRUS BASED
ON GENOME...
antiviralintelistrat.com
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
46. END OF LECTURE 2
Date
Marilen M. Parungao-Balolong 2011 Reference: Chapter 3 Carter And Saunders, 2007)
Thursday, June 30, 2011
