Partenaires
Rechercher
Accueil du site > Animations Scientifiques > Séminaires 2007 > What determines the size of virus ?
What determines the size of virus ?
par Webmaster - 27 juin 2007
Orateur :
William Gelbart, The Virus Research Group, UCLA Department of Chemistry and Biochemistry, Los Angeles, USA
Salle : 118
Sujet :
The fact that the genomes of all viruses contain only a small number of genes (a few to a hundred), and that their protein capsids must be just large enough to protect them, implies a generic size of order 50 nm and — less obviously — icosahedral symmetry. Furthermore, the genomes of most bacterial viruses are double-stranded (ds) DNA, while those of most plant and animal viruses are single-stranded (ss) RNA. In this talk I discuss our lab’s theoretical and experimental work on three particular bacterial, plant, and animal viruses : lambda, cowpea chlorotic mottle virus, and Sindbis, respectively. I argue that the sizes of the genomes correlate with the sizes of their capsids according to the very different physical properties of dsDNA and ssRNA, specifically from the fact that the former is a stiff, linear, homopolymer while the latter is a flexible, heteropolymer with essentially undetermined secondary and tertiary structure. I describe various phenomenological theories used to predict and interpret capsid pressures in the case of dsDNA viruses, and measured radii of gyration and hydrodynamic radii from small-angle X-ray and fluorescence correlation spectroscopy experiments in the case of ssRNA viruses.
Dans la même rubrique :
- Discrete breathers in nonlinear network models of proteins
- Conservative behavior of the biological complex system [Telomeres-Telomerase-Prolifération]
- Linking molecular mechanisms to the organism’s physiology using transcriptomics
- Electron-donor modified nanoparticles for selected cell labeling and photodynamic therapy
- Soutenance d’HDR:Les modes normaux de basse fréquence des protéines
- Human monoclonal antibodies against viruses and cancer
- Vésicules biomimétiques à base de PIP2 pour étudier des interactions protéines membranes : application à une protéine de la famille des ERM (ezrine, radixine, moésine).
- Structural insights into base damage recognition and removal by the Fpg DNA glycosylase
- Transcription by yeast RNA polymerase III and Chromatin Remodeling
- Distinct roles of core histones, histone variants and linker histones in chromatin function
- DNA : More than just a ladder
- Chromatin dynamics in interphase
- On the role of the retroviral Gag protein and the RNA in virus assembly
- Cytoskeleton dynamics involved in cell morphology control and multicellular stability
- Molecular mechanisms of gene transcription and DNA repair in living cells
- Models for the interaction between antibiotic peptides and lipid bilayers - Modèles pour l’interaction entre des peptides antibiotiques et des bicouches lipidiques
- Small Molecule Modulators of Chromatin Modifying Enzymes : To Probe Eukaryotic Transcription and To Target Diseases
- Exploration électrochimique de la dynamique de brins courts d’ADN ancrés sur une surface
- The nucleosome : A transparent, slippery, sticky and yet stable DNA-protein complex
- Histone H1 is a architectural molecule required for chromatin compaction, and is redundant for gene repression
