Detection of nm-scale Motion
Researchers in Taekjip Ha's group have invented a hybrid technique to probe the dynamics of the Holliday junction, a four-stranded DNA structure that forms when damaged DNA is repaired. Understanding how DNA repairs itself is an essential step in ultimately developing effective therapies for genetic disorders.
"Based on our previous studies, we knew the Holliday junction fluctuated between two structures, but how it moved from one place to the other and what intermediates were visited along the pathway were unknown," Ha said. With this latest work, the researchers have determined that the intermediate structure is similar to a Holliday junction, bound to its own processing enzyme.
The hybrid technique combines pico-newton force control provided by an optical trap with the precise measurement capabilities of single-molecule fluorescence energy transfer. Read the paper...
The work was funded by the National Science Foundation and the National Institutes of Health. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the funding agencies.