Poster Presentation The 47th Lorne Conference on Protein Structure and Function 2022

The role of the helicase in DNA replication: A single-molecule study (#229)

Richard R Spinks 1 , Lisanne Spenkelink 1 , Slobodan Jergic 1 , Nicholas Dixon 1 , Antoine van Oijen 1
  1. Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia

Across all life, helicase enzymes exist to catalyse DNA unwinding. In DNA replication however, a dedicated helicase is uniquely designed to coordinate with the other replication proteins to successfully duplicate the genome.

Building on a solid 50–60-year foundation of replication research, we sought to develop single-molecule methods to probe the intimate coordination of the replicative helicase with the other components of the bacterial replisome.

The outcome these experiments were truly unexpected. We found that despite being an ATPase, the helicase does not utilize this function during replication. In fact, it is the polymerase and not the helicase, which is the main driver of DNA unwinding in replication (1).

Now questioning the role of the helicase in replication, we showed that the helicase is still essential and is the main factor determining the stability of the replisome complex throughout replication (2).

  1. Spenkelink, L.M., et al., The E. coli helicase does not use ATP during replication. bioRxiv, 2021: p. 2021.07.07.451541.
  2. Spinks, R.R., et al., DnaB helicase dynamics in bacterial DNA replication resolved by single-molecule studies. Nucleic Acids Res, 2021. 49(12): p. 6804-6816.