In 5 years, new medical labs on a chip will serve as nanotechnology health detectives – tracing invisible clues in our bodily fluids and letting us know immediately if we have reason to see a doctor. The goal is to shrink down to a single silicon chip all of the processes necessary to analyze a disease that would normally be carried out in a full-scale biochemistry lab. Rest
Abstract: Binding of the Origin Recognition Complex (ORC) to origins of replication marks the first step in the initiation of replication of the genome in all eukaryotic cells. Here, we report the structure of the active form of human ORC determined by X-ray crystallography and cryo-electron microscopy. The complex is composed of an ORC1/4/5 motor module lobe in an organization reminiscent of the DNA polymerase clamp loader complexes. A second lobe contains the ORC2/3 subunits. The complex is organized as a double-layered shallow corkscrew, with the AAA+ and AAA+-like domains forming one layer, and the winged-helix domains (WHDs) forming a top layer. CDC6 fits easily between ORC1 and ORC2, completing the ring and the DNA-binding channel, forming an additional ATP hydrolysis site. Analysis of the ATPase activity of the complex provides a basis for understanding ORC activity as well as molecular defects observed in Meier-Gorlin Syndrome mutations. Full article
A global research team has built five new synthetic yeast chromosomes, meaning that 30 percent of a key organism’s genetic material has now been swapped out for engineered replacements. This is one of several findings of a package of seven papers published March 10 as the cover story for Science.
Led by NYU Langone geneticist Jef Boeke, PhD, and a team of more than 200 authors, the publications are the latest from the Synthetic Yeast Project (Sc2.0). By the end of this year, this international consortium hopes to have designed and built synthetic versions of all 16 chromosomes—the structures that contain DNA—for the one-celled microorganism Baker’s yeast, known as S. cerevisiae.
Like computer programmers, scientists add swaths of synthetic DNA to—or remove stretches from—human, plant, bacterial, or yeast chromosomes in hopes of averting disease, manufacturing medicines, or making food more nutritious. Baker’s yeast have long served as an important research model because their cells share many features with human cells, but are simpler and easier to study. Rest