Hi, I know there is a tool and command "build". But it is not that interactive. I wonder if there is a feature in ChimeraX (or any other tools) that can allow the user to draw in 3D space (or 2D) lines and then specify some segments as alpha-helices and some other segments as beta-sheets. I imagine the generated structure can be a backbone populated with G (glycine). Thanks, Roden -- This message and its contents, including attachments are intended solely for the original recipient. If you are not the intended recipient or have received this message in error, please notify me immediately and delete this message from your computer system. Any unauthorized use or distribution is prohibited. Please consider the environment before printing this email.