Presents the Friday Keck Center Teleconference (Live from UTMB)*
Observing the Structural Variability of Viruses in Space and Time.
Alasdair C. Steven, Ph.D.,
Laboratory of Structural Biology, National Institute of Arthritis, Musculoskeletal and Skin Diseases, NIAMS/NIH
4:00 pm Friday
7th April., 2006
(Refreshments at 3:45)
5.521 Levin Hall
Abstract: For viruses, as with other macromolecular assemblies, knowledge of their three-dimensional structures is key to understanding their functional attributes - in particular, their ability to self-assemble, their capability to infect host cells, and their antigenic character. A major step towards elucidating virus structures was taken some 20 years ago, when cryo-electron microscopy was combined with digital image reconstruction to yield the first 3D representations of icosahedral viruses in their native states. Since then, remarkable progress has been made in both the numbers of viruses analyzed in this way and the resolution achieved - now below 1 nm in a growing number of cases. However, this approach, powerful as it is, has drawbacks. First, viruses are dynamic machines and static representations of them are inevitably limited in their implications. Second, many viruses are not icosahedrally symmetric and cannot be analyzed in this way; and viruses with icosahedral capsids also have other components that do not observe this symmetry. This talk will discuss (i) recent developments in computational analysis that transform cryo-EM into a time-resolved imaging technique, as applied to virus assembly; and (ii) cryo-electron tomography, which affords three-dimensional representations of individual asymmetric and pleiomorphic viruses. Applications will focus on the herpesviruses; their distant but direct relatives, the tailed bacteriophages; and recent work on retroviruses. ( http://www.niams.nih.gov/rtbc/labs_branches/lsbr/personnel/stevena.htm ).
RECEPTION TO FOLLOW in 1.200 MRB, the NEW
W. M. Keck Center for Virus Imaging
