Parental histone transfer caught at the replication fork. (https://pubmed.ncbi.nlm.nih.gov/38448592/)

These scientists used a special technique called cryo-electron microscopy to look at how DNA is copied in yeast cells. In our bodies, DNA is wrapped around proteins called histones to form structures called nucleosomes. When DNA is copied during cell division, the histones also need to be copied and passed on to the new cells to keep important information intact.

The scientists found that a complex called FACT, which helps with moving and changing the structure of chromatin (the combination of DNA and histones), is located at the front of the machinery that copies DNA, called the replisome. FACT interacts with the parental DNA and helps capture the histones that need to be copied.

They discovered that the histones are held together in a specific way during the copying process. Some parts of the histones are grabbed by FACT, while other parts are held by another protein called Mcm2. This arrangement helps move the old histones to the front of the replisome so they can be transferred to the newly made DNA.

By understanding how histones are recycled during DNA copying, these scientists gained important insights into how cells maintain important information as they divide.

Li N., Gao Y., Zhang Y., Yu D., Lin J., Feng J., Li J., Xu Z., Zhang Y., Dang S., Zhou K., Liu Y., Li XD., Tye BK., Li Q., Gao N., Zhai Y. Parental histone transfer caught at the replication fork. Nature. 2024 Mar 6. doi: 10.1038/s41586-024-07152-2.