Functioning Protein with Atomic-level Precision

Graphic: A process at the DNA

Writing in the November 13 online issue of the journal Nature, the Stanford researchers explain how the new instrument allowed them to settle long-standing scientific debates about the way genes are copied from DNA.

"In the Nature experiment, we carried out the highest-resolution measurement ever made of an individual protein," says Steven Block, professor of applied physics and of biological sciences. "We obtained measurements accurate to one angstrom, or one-tenth of a nanometer. That's a distance equivalent to the diameter of a single hydrogen atom, and about 10 times finer than any previous such measurement."

The development of an ultra-stable optical trapping system with angstrom resolution is "a major advance," says Charles Yanofsky, the Morris Herzstein Professor of Biological Sciences at Stanford and a pioneer of modern molecular genetics. The new device is like "adding movies to stills in understanding enzyme action," he says.

"This technical achievement will no doubt lead to new information about the molecular machinery that carries out basic cellular processes, particularly those related to replication, transcription and translation," adds Catherine Lewis, a program director in biophysics at the National Institute of General Medical Sciences (NIGMS).

In a second paper published in the November 8 online issue of the journal Physical Review Letters, the scientists offer a detailed description of their novel device, an advanced version of the "optical trap," which uses infrared light to trap and control the forces on a functional protein, allowing researchers to monitor the molecule's every move in real time.; Source: Stanford University