Across all life, helicase enzymes exist to catalyse DNA unwinding. In the DNA replication process, however, the dedicated ‘replicative helicase’ is uniquely designed to coordinate with the other replication proteins. In the last 50-60 years, research in this field was thought to have confidently established how replicative helicases work – yet, in recent years, emerging single-molecule methods have led to the identification of new behaviours.
As a result of the technological advancements in this ‘single-molecule era’, the rules for replicative helicases are being re-written with hints that these enzymes have other roles beyond that of a regular helicase. Building on these recent advancements, the work of this PhD sought to develop single-molecule methods to detect dynamics in the activity of the bacterial replicative helicase within ongoing DNA replication.
The results of this PhD identified two unique traits: 1) The bacterial replicative helicase has a high innate stability amongst an otherwise transient replication complex. 2) This helicase can use ATP to power unwinding, but it does not utilise this function during the replication. This effectively renders DNA replication an ATP-independent process.