Single-molecule visualization of Saccharomyces cerevisiae leading-strand synthesis reveals dynamic interaction between MTC and the replisome

Watching the machines that make DNA

29 March 2018

Single-molecule imaging techniques have enabled researchers to reveal the workings of the replisome, the molecular machinery that replicates DNA.

A team including researchers from the University of Wollongong investigated the activity of a minimal replisome, the smallest assembly capable of replicating DNA. They tethered DNA molecules to a microscope slide and observing the replication process in real time. By observing individual molecules, the precision was greater than that which comes from averaged observations of an ensemble of molecules.

Their findings highlighted important roles for two additional factors related to replication, the protein Mcm10, and the protein complex MTC. Addition of Mcm10 increased the number of active replisomes and thus the rate of replication, suggesting that it is involved in assembling or stabilizing the complex. Addition of the MTC complex also increased the replication rate. MTC transiently interacts with the replisome. Since MTC is known to respond to DNA damage, this transient interaction may facilitate the fine-tuning of DNA replication in response to damage.

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References

1. PNAS 114, 10630-10635 (2017). doi: 10.1073/pnas.1711291114