Structure, function and dynamics of nuclear subcompartments.

The nucleus contains a plethora of different dynamic structures involved in the regulation and catalysis of nucleic acid metabolism and function. Over the past decades countless factors, molecular structures, interactions and posttranslational modifications have been described in this context. On the one side of the size scale X-ray crystallography delivers static snapshots of biomolecules at atomic resolution and on the other side light microscopy allows insights into complex structures of living cells and tissues in real time but poor resolution. Recent advances in light and electron microscopy are starting to close the temporal and spatial resolution gap from the atomic up to the cellular level. Old challenges and new insights are illustrated with examples of DNA replication and nuclear protein dynamics.