Work at Purdue and The Catholic University of America has clarified how a natural nanotechnology motor works to “pump” DNA into the head of a virus. From Small Times:

The virus consists of a head and tail portion. The DNA-packaging motor is located in the same place where the tail eventually connects to the head. The motor falls off after the packaging step is completed, allowing the tail to attach to the capsid.

DNA is made of four different kinds of “nucleotides” identified by a specific “base.” The bases are paired together to form the rungs of a ladderlike, double-stranded helical structure. Because there is a negative charge associated with each nucleotide, they repel each other when compressed together, creating a pressure inside the confining space of the capsid. A motor is needed to counteract this pressure, in effect pumping the DNA into the head…

The authors proposed that the motor uses a similar inchworm mechanism to package the DNA into the virus…

Because herpes and other viruses contain similar DNA packaging motors, the findings could help scientists to design drugs that would interfere in the function of these motors and hence mitigate the result of some viral infections. The findings also could have other applications, such as development of tiny “nanomotors” in future machines, [Purdue biology prof Michael] Rossmann said.

Nature’s nanotech: a great inspiration for today’s nanotechnologists. —Christine