Physics goes DNA: from base-pairs to chromatin

DNA carries the genetic information and is thus at the heart of many biological processes like transcription, replication and DNA repair. The picture in recent years has moved away from considering DNA just as a passive carrier of information and it is appreciated more and more that the physical properties of DNA have a strong impact on its function. To give an example: very recently it has been discovered that there is a second "code" superimposed on top of the classical genetic code (codons of three bases encoding for aminoacids). This second code is possible due to redundancy of the genetic code (64 codons but only 20 amino acids) and controls some of the mechanical properties of the DNA chain. This is crucial since three quarter of our DNA is wrapped around protein spools, so-called nucleosomes, and this second code is largely responsible for the location of the nucleosomes. The spacing of the nucleosomes along the DNA in turn controls the larger scale structures of the resulting so-called chromatin complex: presumably the geometry and stability of a 30 nm wide chromatin fiber and maybe even the structures of its whole chromosome. The necessity for this complex hierarchical structure lies in the fact that the DNA chains have macroscopic lengths but need to fit into the micron-sized cell nucleus. By neatly folding it all the necessary processes can take place but how this works in detail is hotly debated and subject of current research.

With structures ranging from nanometer (basepair) to micrometers (chromosomal domain in a nucleus) there is the necessity for a wide range of experimental and theoretical methods. Since all the different length scales are strongly intertwined, it is not possible to understand DNA in its biological environment by just focusing on a single length scale. The purpose of this workshop is to bring together experts that work on the biophysics of DNA on different length scales and to foster a discussion between them.