File:Exploration-of-Uncharted-Regions-of-the-Protein-Universe-pbio.1000205.g005.jpg

English: With growing number of folds, the percentage of folds with partial structural similarity to other folds is increasing, and hence, the number of truly new folds being discovered is rapidly decreasing. Folds were added in historical order in groups of 100 and the percentage of folds with partial similarity to any previously solved fold was calculated for each group. All cases in which FATCAT algorithm found at least 50 equivalent residues superimposed with Cα RMSD <3 Å were regarded as putative cases of “significant partial similarity” and were subject to visual verification. As indicated by a box on the graph, 30% of new folds from DUF families described here show such partial similarities to other protein folds.