The Molecule That Works Against You

By Jane Farrell

Researchers have determined exactly how a “molecular motor” drives a process that invades cells. That finding could be crucial in combating viral infections.

In the study, researchers from the University of California Berkeley reached new conclusions on how a type of molecular motor is used to “package” the DNA of a number of viruses, including herpes and adenoviruses. Once the DNA is packaged in the virus, it can invade the body and cause infection.

In examining the DNA “packaging motor” of a virus known as Phi 29, the researchers also found that the motor doesn’t just exert force on the DNA, but also rotates it for maximum efficiency.

“We were able to follow a viral packaging motor in…different stages of its biological task and discover the multiple and specific ways in which the motor’s mechanisms are modified in response to external signals,” says researcher Carlos Bustamente. “We showed that by designing carefully controlled experiments, it is possible to learn a great deal about the subtle molecular mechanisms underlying the coordination of various molecular motor components.”

Bustamante, a faculty scientist with Berkeley Lab’s Physical Biosciences Division and UC Berkeley’s Raymond and Beverley Sackler Chair of Biophysics, has been a pioneer in the study of single molecules and molecular motors.