Organization of double-stranded DNA in bacteriophages: a study by cryo-electron microscopy of vitrified samples.
AUTOR(ES)
Lepault, J
RESUMO
In this paper it is shown that conformation and packing of double-stranded DNA within the head of bacteriophages lambda and T4 can be assessed by cryo-electron microscopy of vitrified specimens. Electron diffraction patterns show that DNA within vitrified bacteriophages has a B conformation. Electron micrographs of vitrified bacteriophages show domains within the head formed by a approximately 2.5-nm striation and arising from the DNA packing. The number of differently oriented domains seen within a vitrified bacteriophage depends upon the geometry of the DNA container: the bacteriophage capsid. The packing of DNA within bacteriophages seems then to be governed by at least two phenomena. The first is the tendency of DNA to form local alignments (nematic liquid crystals). The second is the orientation of these liquid crystals by the bacteriophage capsid. From these observations we propose a possible packaging mechanism: constrained nematic crystallization.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=553958Documentos Relacionados
- Cryo-electron microscopy of vitreous sections
- Subdomain organization of the Acanthamoeba myosin IC tail from cryo-electron microscopy
- Structure of a viral DNA gatekeeper at 10 Å resolution by cryo-electron microscopy
- The three-dimensional structure of reovirus obtained by cryo-electron microscopy.
- Cryo-electron microscopy structure of yeast Ty retrotransposon virus-like particles.
