Slip-sliding away…

In the cell nucleus, the genomic DNA is packaged into a tightly condensed form, which is referred to as chromatin. The basic unit of chromatin organization is the nucleosome, a DNA-protein complex consisting of a defined length of DNA wrapped around a bead-like structure which is made of histone proteins. The individual nucleosomes are connected by a short length of linker DNA, forming a string of beads which are in turn packed together by special cross-linking proteins. The detailed structure of chromatin regulates access to the genes, and therefore plays a vital role in the control of gene expression. In response to metabolic signals, environmental changes and developmental processes, mechanisms are triggered that dynamically modify chromatin structure, making genes accessible for activation whose products enable the cell to adapt to changes in local conditions. Large protein complexes called chromatin remodellers play a central role in this process. These molecular machines act locally to disrupt the contacts between nucleosomal histones and DNA and effectively slide the nucleosome along the DNA. Now a research group led by Professor Karl-Peter Hopfner at LMU’s Gene Center in collaboration with a team around Dr. Philipp Korber at the Biomedical Center, has dissected the function of an important module of the remodeller INO80 in this process. The new findings have just been published in the journal Nature Structural & Molecular Biology.