Relative to its size, a molecular motor used by viruses is twice as powerful as an automobile engine. That's why even very large viruses can self-assemble so rapidly.
Researchers used laser tweezers to measure forces generated by the nanoscale motor that packs DNA into a virus during the assembly of an infectious virus particle. This power allows the virus to reel in its long genome with remarkable speed.
“The genome is about 1,000 times longer than the diameter of the virus,” explained Douglas Smith, an assistant professor of physics at UCSD and co-author of the study. “It is the equivalent of reeling in and packing 100 yards of fishing line into a coffee cup, but the virus is able to package its DNA in under five minutes.”
The researchers say that their work could ultimately lead to better ways of designing antiviral medications. Drugs that target the DNA-packaging process could block the infection cycle by preventing viral assembly. Such drugs could also interfere with the ability of the virus to inject its DNA into the cells it infects because injection is facilitated by the high pressure at which the genetic material is packaged within the virus’ outer shell.