Chapter 6: Replication, Maintenance and Rearrangements of Genomic DNA

Video 6.1 DNA Replication

This animation is of a DNA replication fork and the molecular machinery that drives this process. The machinery is a multi-enzyme complex known as a replisome, containing a number of specialized proteins. This animation was built as a "hybrid" of prokaryote and eukaryote replication proteins and dynamics. The speed of replication in this animation is based on a eukaryote system (20–50 bases/second, with Okazaki fragments 100–150 bases long). The bacterial (prokaryotic) replisome works about 10 times faster. In a replisome, two tau subunits (light blue) connect the DNA helicase (dark blue) to the clamp loader (grey fingers), and each tau connects to one of the two polymerase (purple) enzymes. The other two proteins that feature in this animation are sliding clamps (green) and the DNA primase (yellow-green), which adds RNA primers (yellow) to the ssDNA as it emerges from the helicase. (1.3 MB) [© HHMI.]