In this week's Science, a team led by researchers from Montana State University publish the crystal structure of the CRISPR RNA-guided surveillance complex in Escherichia coli. CRISPR is part of an adaptive immune system in bacteria and is being adapted as a research tool and potential therapeutic. In E. coli, CRISPR-derived RNAs form a protein complex known as Cascade that helps detect invading DNA. By determining the x-ray crystal structure of Cascade — its 11 proteins and the short CRISPR-derived RNAs form a sea-horse-shaped complex, as the researchers describe it, that binds double-stranded DNA targets that are complementary to the crRNA-guide sequence — the scientists have shed light on the features required for its assembly and its methods of target recognition.
Meanwhile, in Science Translational Medicine, Duke University law professor Arti Rai and her student Grant Rice argue that so-called use patents, which cover new uses for existing drugs and have been derided as a way to artificially extend patent life, can have commercial and therapeutic value. The duo points to instances where use patents can breath new life into a failed drug candidate and help de-risk its development for new indications. They warn that securing and enforcing use patents can be challenging, but that their potential value makes such efforts worthwhile.