Physics of viral infectivity: Matching genome length with capsid size

In this work, we review recent advances in the field of physical virology, presenting both experimental and theoretical studies on the physical properties of viruses. We focus on the double-stranded DNA (dsDNA) bacteriophages as model systems for all of the dsDNA viruses both prokaryotic and eukaryotic. Recent studies demonstrate that the DNA packaged into many dsDNA viral capsids is highly pressurized, which provides a force for the first step of passive injection of viral DNA into either bacterial or eukaryotic cells. Moreover, specific studies on capsid strength show a strong correlation between genome length and capsid size and robustness. The implications of these newly appreciated physical properties of a viral particle with respect to the infection process are discussed.