| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1996929 | Molecular Cell | 2010 | 12 Pages |
SummaryHow DNA repair proteins sort through a genome for damage is one of the fundamental unanswered questions in this field. To address this problem, we uniquely labeled bacterial UvrA and UvrB with differently colored quantum dots and visualized how they interacted with DNA individually or together using oblique-angle fluorescence microscopy. UvrA was observed to utilize a three-dimensional search mechanism, binding transiently to the DNA for short periods (7 s). UvrA also was observed jumping from one DNA molecule to another over ∼1 μm distances. Two UvrBs can bind to a UvrA dimer and collapse the search dimensionality of UvrA from three to one dimension by inducing a substantial number of UvrAB complexes to slide along the DNA. Three types of sliding motion were characterized: random diffusion, paused motion, and directed motion. This UvrB-induced change in mode of searching permits more rapid and efficient scanning of the genome for damage.
Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (318 K)Download as PowerPoint slideHighlights► The NER proteins UvrA/B were quantum-dot-tagged and visualized on DNA tightropes ► UvrA binds to DNA on average for 7 s and can hop between strands up to 1 μm ► UvrB alters UvrA's search mechanism to include several forms of 1D sliding ► Dual color imaging indicates UvrA coordinates the formation of a UvrA2B2 complex
