Prelim 2 study guide

Prelim 2 study guide - Lecture 6 Virus Structure P2...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Lecture 6: Virus Structure P2: Function of viral particles include: protecting the genome, having genetic economy so capsid made from one protein, and being able to deliver from cell to cell Methods to Study Virus Structure – Pages 6-7, Book 86-89-Transmission electron microscopy: thin section needed, really bad for details-Cyro-EM: freezing of virus particles allows 3D structure, avoids water crystal formation; pretty good resolution- X-Ray Crys: the best resolution since u can actually see the molecular interactions between particles, but need high concentration of highly purified particle Enveloped Viruses (Page 4, book 114)-has a lipid bilayer that is acquired through budding from host membranes- envelope has multiple viral glycoproteins, which were localized to the cell membrane first before budding- nucleocapsid: nucleic acid, protein shell, envelope 1) VSV (Page 5)- G protein is synthesized an enters secretory pathway where it goes to plasma membrane- Virus proteins will interact with cytoplasmic side of G protein to help, these internal domains essential for virus assembly 2) Influenza Naked Viruses (Page 5)- protein capsid assembled in cytoplasm or nucleus- capsid: protein shell and nucleic acid 1) Poliovirus: naked icosahedron- has VP1, VP2 and VP3, to make a capsid- assembly coupled with genome replication (a +RNA virus) 2) Adenovirus: naked icosahedron , has fibers with knobs for attachment Capsid Structures (Pages 8- Subunit= single polypeptide Protomer/Asymmetric unit: a building block of capsid, 1+ subunits Two main structures: 1) Helical (Pages 9-10)- helical animal viruses are always enveloped- helix formed from single subunit and can be as long as possible- EXAMPLE: TMV- page 10: disc to dishwasher conformation as the RNA is threaded through 2) Icosahedral (Pages 10-13)- has 20 equilateral triangles with various axis of symmetry- each triangle has 3 subunits, so need 20*3= 120 subunits to make basic capsule- Triangulation Number : Page 12 T = (# subunits) / 60 T = (# protomers) / 3- for larger capsids, becomes difficult and quasi-equivalence happens Page 14-15: Interactions b/t protein subunits: are all NONCOVALENT (h-bonding, salt bridges, hydrophobic and van der waals interactions) 3) T4: syringe mechanism, assembly is very complicated 4) Reovirus and Rotavirus: a couple of protein shells Lecture 7: Virus Binding and Entry Things in the host cell surface: Pages 3 and 4 1) Attachment Factors : they are not required, make initial contact, are non-specific and concentrated, binding is reversible and does not change conformation, 2) Receptors and co-receptors...
View Full Document

Page1 / 19

Prelim 2 study guide - Lecture 6 Virus Structure P2...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online