title: Polymorphism of DNA conformation inside the bacteriophage capsid.
abstract: Double-stranded DNA bacteriophage genomes are packaged into their icosahedral capsids at the highest densities known so far (about 50 % w:v). How the molecule is folded at such density and how its conformation changes upon ejection or packaging are fascinating questions still largely open. We review cryo-TEM analyses of DNA conformation inside partially filled capsids as a function of the physico-chemical environment (ions, osmotic pressure, temperature). We show that there exists a wide variety of DNA conformations. Strikingly, the different observed structures can be described by some of the different models proposed over the years for DNA organisation inside bacteriophage capsids: either spool-like structures with axial or concentric symmetries, or liquid crystalline structures characterised by a DNA homogeneous density. The relevance of these conformations for the understanding of DNA folding and unfolding upon ejection and packaging in vivo is discussed.
authors.affiliation: Laboratoire de Physqiue des Solides, CNRS, UMR 8502, Université Paris Sud, Orsay, France. amelie.leforestier@u-psud.fr
authors.forename: Amélie
authors.initials: A
authors.lastname: Leforestier
mesh_terms: D001435:Bacteriophages; D002213:Capsid / Q000737:chemistry / Q000378:metabolism*; D002412:Cations / Q000494:pharmacology; D042003:DNA Packaging / Q000187:drug effects; D004279:DNA, Viral / Q000737:chemistry* / Q000235:genetics; D009690:Nucleic Acid Conformation / Q000187:drug effects; D009997:Osmotic Pressure
chemical_list: D002412:Cations; D004279:DNA, Viral