Once you are viewing a record of interest in the NCBI BioSystems Database, simply follow the link for "Other Links: Structures"
- The 3D protein structures associated with a biosystem are identified using the method described in the help document.
- Those 3D structures are accessible by selecting the Other links: Structures option in the "Related information" menu that appears in the right hand margin of an individual biosystem record, or in the "Find Related Data" menu that appears in the right hand margin of a search results pages.
- The 3D protein structures can then be viewed with Cn3D, a free helper application available for Windows, Macintosh, and Unix platforms. Cn3D installation takes only a couple of minutes and a tutorial describes the program's features and functions.