title: Pocket similarity: are alpha carbons enough?
abstract: A novel method for measuring protein pocket similarity was devised, using only the alpha carbon positions of the pocket residues. Pockets were compared pairwise using an exhaustive three-dimensional Calpha common subset search, grouping residues by physicochemical properties. At least five Calpha matches were required for each hit, and distances between corresponding points were fit to an Extreme Value Distribution resulting in a probabilistic score or likelihood for any given superposition. A set of 85 structures from 13 diverse protein families was clustered based on binding sites alone, using this score. It was also successfully used to cluster 25 kinases into a number of subfamilies. Using a test kinase query to retrieve other kinase pockets, it was found that a specificity of 99.2% and sensitivity of 97.5% could be achieved using an appropriate cutoff score. The search itself took from 2 to 10 min on a single 3.4 GHz CPU to search the entire Protein Data Bank (133 800 pockets), depending on the number of hits returned.
authors.affiliation: Chemical Computing Group, Inc., 1010 Sherbrooke Street West, Suite 910, Montreal, Quebec, Canada H3A 2R7. hfeldman@chemcomp.com
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Feldman
authors.forename: Paul
authors.initials: P
authors.lastname: Labute
mesh_terms: D001665:Binding Sites; D002244:Carbon / Q000737:chemistry*; D002826:Chorismate Mutase / Q000737:chemistry; D016000:Cluster Analysis; D030562:Databases, Protein; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D011487:Protein Conformation; D011494:Protein Kinases / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D014448:Tyrosine-tRNA Ligase / Q000737:chemistry
chemical_list: D008024:Ligands; D011506:Proteins; D002244:Carbon; D011494:Protein Kinases; D002826:Chorismate Mutase; D014448:Tyrosine-tRNA Ligase