Molecular Road Roller
University of Illinois Physics professor Taekjip Ha and his former graduate student, Rahul Roy in collaboration with Timothy Lohman's laboratory at Washington University at St. Louis applied advanced single molecule fluorescence techniques to reveal remarkable motions of SSB on DNA. In a recent article reported in journal Nature (Nature 461(7267):1092-7 (2009)), they discovered that SSB that was long thought to be static when bound to DNA was actually roaming rapdidly all over the DNA. Furthermore, SSB could act as a 'molecular road roller' by removing kinks, so called secondary structures, that are spontaneously formed by the DNA. This function was biologically important because RecA proteins that are necessary for DNA repair could bind to the single stranded DNA only when SSB would remove such obstacles. An artist’s rendition of SSB (green) in motion on DNA (red) followed by RecA (yellow) proteins forming a filament is shown in the Figure above. Read more about this study at HHMI and UIUC website.
For more information see: http://news.illinois.edu/news/09/1021dna.html