Grath is a graph-based structure comparison algorithm. It rapidly, and accurately, matches a novel structure against a library of domain structures already classified in CATH to find the most similar ones. GRATH uses a measure of similarity that details the geometric information, number of secondary structures and number of residues within secondary structures, that any two protein structures share.

The file lists the name of the protein structure and the number of secondary structure in that structure (as determined by Secmake ). For each of those secondary structures, the first and last residue is given. A list then follows that gives the results comparing of each residue in that structure against all others in the format:

First_Residue_Number First_Residue_Type* Second_Residue_Number Second_Residue_Type Distance_Closest_Approach Pairwise_Angle Dihedral_Angle

Grath output files from different structures can then be compared to see whether they are similar in structure.

For more information please go to this page.

* S = beta strand and H = alpha helix