Smile for the camera, Cpf1
The crystal structure of CPF1 provides some intriguing insights into this CRISPR gene-editing enzyme.
Image courtesy Ian Slaymaker, Zhang lab
Take a good look at the image above. What you're seeing is the first 3D atomic resolution structure of a CRISPR enzyme called Cpf1 (blue-green) embracing a guide RNA (silver) and a target strand of DNA (gold).
Cpf1 came to light last year after an international team led by Broad core institute member Feng Zhang screened hundreds of CRISPR systems in different types of bacteria, searching for enzymes with useful properties that could be engineered for use in human cells.
Today in Cell, the Zhang team in collaboration with the University of Tokyo's Osamu Nureki and Hiroshi Nishimasu announced the structure of the new AsCpf1 enzyme in complex with target DNA, a view that provides some further guidance about how Cpf1 works. The structure provides insights into why Cpf1 leaves its target with staggered ends (as opposed to the blunt end cuts of Cas9), information that could help researchers engineer new Cpf1-based CRISPR gene editing tools.
"The images highlight some amazing features that may account for some of the differences between Cas9 and Cpf1," says Ian Slaymaker, a research fellow in the Zhang lab and an author on the Cell study. "It gives us a different view on the ways in which CRISPR enzymes can precisely target and cut DNA."
Yamano T, Nishimasu H, et al. Crystal structure of Cpf1 in complex with guide RNA and target DNA. Cell. Online April 21, 2016. DOI: 10.1016/j.cell.2016.04.003