Condensed genome structure.
Large, tailed dsDNA-containing bacteriophage genomes are packaged to a conserved and high density (∼500 mg/ml), generally in ∼2.5-nm, duplex-to-duplex, spaced, organized DNA shells within icosahedral capsids. Phages with these condensate properties, however, differ markedly in their inner capsid structures: (1) those with a naked condensed DNA, (2) those with many dispersed unstructured proteins embedded within the DNA, (3) those with a small number of localized proteins, and (4) those with a reduced or DNA-free internal protein structure of substantial volume. The DNA is translocated and condensed by a high-force ATPase motor into a procapsid already containing the proteins that are to be ejected together with the DNA into the infected host. The condensed genome structure of a single-phage type is unlikely to be precisely determined and can change without loss of function to fit an altered capsid size or internal structure. Although no such single-phage condensed genome structure is known exactly, it is known that a single general structure is unlikely to apply to all such phages.
Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201-1503, USA. lblack@umaryland.edu
Lindsay W
LW
Black
Julie A
JA
Thomas
D001435:Bacteriophages / Q000235:genetics*; D002213:Capsid / Q000502:physiology / Q000648:ultrastructure; D004279:DNA, Viral / Q000648:ultrastructure*; D016679:Genome, Viral; D008958:Models, Molecular; D011487:Protein Conformation; D014764:Viral Proteins / Q000737:chemistry; D019065:Virus Assembly
D004279:DNA, Viral; D014764:Viral Proteins