title: Discriminating between homodimeric and monomeric proteins in the crystalline state.
abstract: Scores calculated from intermolecular contacts of proteins in the crystalline state are used to differentiate monomeric and homodimeric proteins, by classification into two categories separated by a cut-off score value. The generalized classification error is estimated by using bootstrap re-sampling on a nonredundant set of 172 water-soluble proteins whose prevalent quaternary state in solution is known to be either monomeric or homodimeric. A statistical potential, based on atom-pair frequencies across interfaces observed with homodimers, is found to yield an error rate of 12.5%. This indicates a small but significant improvement over the measure of solvent accessible surface area buried in the contact interface, which achieves an error rate of 15.4%. A further modification of the latter parameter relating the two most extensive contacts of the crystal results in an even lower error rate of 11.1%.
authors.affiliation: EMBL Outstation, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Ponstingl
authors.forename: K
authors.initials: K
authors.lastname: Henrick
authors.forename: J M
authors.initials: JM
authors.lastname: Thornton
mesh_terms: D003460:Crystallization; D019281:Dimerization; D011506:Proteins / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011506:Proteins