https://phys.org/news/2018-10-proteins-dna-replication-drosophila.html

"We knew that the Suppressor of Underreplication (SUUR) protein was involved in slowing down the replication machinery, but we didn't know how it worked," Nordman said. "In fruit flies, which have all the machinery necessary to copy DNA virtually identically to humans, the SUUR protein physically interacts with the Rif1 protein, bringing it to the train. Once there, Rif1 has the capacity to inhibit or slow down replication."

Rif1 controls how much DNA gets copied in human cells too, but nobody knows how it does this job. While humans don't have SUUR, they likely use another adaptive protein to help Rif1 slow down the replication machinery. This work was the foundation for a new National Science Foundation grant to interrogate how the Rif1 protein controls DNA replication, Nordman said.