Single-molecule studies of DNA replication

The replication of DNA plays a central role in transmitting hereditary information from cell to cell. Our DNA is replicated by a little machine consisting of several proteins, which all have different tasks but work closely together. For example, one of the proteins unzips the double-stranded DNA, revealing two single strands. Those single strands are then each transformed into a double strand again, resulting now in two identical copies of the original DNA.

It is known that the proteins within the replication-machine dynamically interact, but how does this work exactly? With a complex machine such as a racing car, different components, for example wheels, can be replaced during a pit stop. Do proteins get exchanged within the replication machines as well? In this study, we are aiming to answer these questions by visualizing the proteins in the machines at a single-molecule level, developing and using fluorescence microscopy techniques similar to those that were honored this year with the Noble Prize for Chemistry. By zooming in on the behavior of individual proteins within the replication machinery, we have obtained new insights in the critical and regulatory interactions within the apparatus that replicates DNA.