Screenshot of the domain 3cx5B01 in the CATH browser. The domain is classified as 3.30.830.10, which means that it belongs to the Mixed Alpha-Beta class (C = 3), the 2-Layer Sandwich architecture (A = 30) and so forth. The CATH Code column allows for easy browsing both up and down levels in the hierarchy, and the Links column provides links to relevant entries in the Gene3D database. An XML file containing all information on the page can be downloaded by clicking on the XML link next to the domain name. The icon below the image links to a structure file in the Rasmol format. The panes in the bottom of the screen provide additional information about the domain. The content of the Structure pane, which contains secondary structure information, is shown in the figure. The Sequence pane contains the amino acid sequence of the domain and the History pane contains the history of the domain in CATH, with information about when the domain was added to the database and whether its classification has changed over time.