Then as Chiu and Jiang used the computer visualization tool to strip away the surface shell entirely, they saw the concentric coil of DNA underneath. They also identified a protein "hub" through which DNA enters and exits the virus.
"It's like a garden hose, in some ways," said Chiu. "You extend it. If you put it away in a heap, then you have trouble using it again. But if you coil the hose orderly, then it is easy to use again. I think the virus does the same thing. The virus genome has to enter the capsid during the birth of the virus and then inject into the cell during infection. It has to come in and get out easily. The hub anchors the tail spikes, but is also a conduit for the DNA to get in and out."
Below is the "portal" that acts as a motor using energy to coil the threads of double-stranded DNA. Using the capabilities of his program, Chiu and colleagues identified 12 protein copies that make up this viral motor.
Chiu anticipates using the same technique to study other spherical viruses as soon as he can obtain the computer power to study larger structures. Soon, he said, he hopes to be able to study the interactions of virus and cell more closely.
Others who participated in his study include Juan Chang (a current graduate student in the SCBMB Program) and Joanita Jakana of BCM, Dr. Peter Weigele and Professor Jonathan King of the Massachusetts Institute of Technology. Jiang is now a faculty with Purdue University.