The LabelHash suite of programs and scripts can be used to match point-based structural motifs to a set of target proteins. A motif is defined by the C-alpha positions of a number of residues. Associated with each motif point is a number of allowed residue labels. The targets that are used for matching are preprocessed to built a large table that facilitate quick lookup of parts of a motif. After the targets have been preprocessed and the LabelHash table has been created, it can be used to match any motif (i.e., the table is not specific to a motif). The matching results can be visualized in Chimera with the bundled ViewMatch plugin.
Motif matching can also be done through the LabelHash web server. You can use the LabelHash tools to visualize and further analyze the results. Compared to the web server, the command line tools and the Python module offer more flexibility in how the LabelHash table is constructed and how matching is performed.