In Science this week, researchers from Gilead Sciences report on the crystal structure of NS5B, an RNA polymerase encoded by the hepatitis C virus that replicates the virus's RNA genome, and how the company's HCV therapy sofosbuvir interacts with the active site of the polymerase. To do so, the team analyzed the crystal structures of stalled NS5B complexes containing the polymerase, template RNA, and incoming nucleotides during various stages of RNA synthesis. The findings may help in the development of new drugs targeting the replicative machinery of similar RNA viruses such as West Nile, the researchers say.
And in Science Advances, a team led by investigators at the University of Washington School of Medicine publish data around the identification of two sets of DNA sequences that strongly influence the genetic makeup of human centromeres, and point to the importance of these sequences in centromere evolution. After identifying the sequences, the scientists mapped them and found that the DNA are wrapped around two pillars of histones and proteins. If reproducible, these "twin pillars" may serve as the foundation for artificial chromosome production.