Cas9 (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption The crystal structure of SpyCas9 features a nuclease domain lobe (red) and an alpha-helical lobe (gray) each with a nucleic acid binding cleft that becomes functionalized when Cas9 binds to guide RNA. Credit Image courtesy of Doudna, Nogales, et. al Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.