Structures and their pocket measurements can be fetched directly from the Computed Atlas of Surface Topography of proteins (CASTp) database or read from local files previously returned by the CASTp server. In Chimera, the pockets are shown in a pocket list. Choosing rows in the list performs actions such as zooming in on pockets and selecting the surrounding atoms.

The figure shows the four largest pockets by volume identified by CASTp for PDB entry 1ovh (a cavity mutant of T4 lysozyme), shown in yellow, orange, pink, and magenta in order of decreasing volume. The largest is lysozyme's active site, with two openings. The second largest is the engineered cavity. Mutated positions are shown in red. Green balls are Cl^– ions.

The image shows the structure of the human TRPA1 ion channel (wasabi receptor) determined by electron cryo-microscopy, Protein Data Bank entry 3j9p. The four subunits of the tetramer are shown as ribbons in different colors over a dark-to-light gradient background. (More samples...)