it was discovered that RSC is required for nucleosome remodeling. There is evidence that RSC does not remodel the nucleosomes on its own; it uses information from enzymes to help position nucleosomes. The ATPase activity of the RSC complex is activated by single-stranded, double-stranded, and/or nucleosomal DNA, while some of the other chromatin remodeling complexes are only stimulated by one of these DNA-types. The RSC complex (specifically Rsc8 and Rsc30) is crucial when fixing double-stranded breaks via non-homologous end joining (NHEJ) in yeast. This repair mechanism is important for cell survival, as well for maintaining an organism's genome. These double-stranded breaks are typically caused by radiation, and they can be detrimental to the genome. The breaks can lead to mutations that reposition a chromosome and can even lead to the entire loss of a chromosome. The mutations associated with double-stranded breaks have been linked to cancer and other deadly genetic diseases. RSC does not only repair double-stranded breaks by NHEJ, it also repairs this breaks using homologous recombination with the help of the SWI/SNF complex. SWI/SNF is recruited first, prior to two homologous chromosomes bind, and then RSC is recruited to help complete the repair. Mechanism of Action in dsDNA A single molecule study using magnetic tweezers and linear DNA observed that RSC generates DNA loops in vitro while simultaneously generating negative supercoils in the template. These loops can consist of hundreds of base pairs, but the length depends on how tightly the DNA is wound, as well as how much ATP is present during this translocation. Not only could RSC generate loops, but it was also able to relax these loops, meaning that the translocation of RSC is reversible. Hydrolysis of ATP allows the complex to translocate the DNA into a loop. RSC can release the loop either by translocating back to the original state at a comparable velocity, or by losing one of its two contacts. RSC components The following is a list of RSC components that have been identified in yeast, their corresponding human orthologs, and their functions: See also SWI/SNF (nucleosome remodeling complex) Mi-2/NuRD complex INO80B (gene) Imitation SWI (nucleosome remodeling complex) References External links Dynamic Remodeling of Individual Nucleosomes Across a Eukaryotic Genome in Response to Transcriptional Perturbation Enzymes Transcription coregulators