title: Symmetric structures in the universe of protein folds.
abstract: Insights in structural biology can be gained by analyzing protein architectures and characterizing their structural similarities. Current computational approaches enable a comparison of a variety of structural and physicochemical properties in protein space. Here we describe the automated detection of rotational symmetries within a representative set of nearly 10,000 nonhomologous protein structures. To find structural symmetries in proteins initially, equivalent pairs of secondary structure elements (SSE), i.e., alpha-helices and beta-strands, are assigned. Thereby, we also allow SSE pairs to be assigned in reverse sequential order. The results highlight that the generation of symmetric, i.e., repetitive, protein structures is one of nature's major strategies to explore the universe of possible protein folds. This way structurally separated 'islands' of protein folds with a significant amount of symmetry were identified. The complete results of the present study are available at http://agknapp.chemie.fu-berlin.de/gplus, where symmetry analysis of new protein structures can also be performed.
authors.affiliation: Freie Universität Berlin, Department of Chemistry and Biochemistry, Fabeckstrasse 36a, 14195, Berlin, Germany.
authors.forename: Aysam
authors.initials: A
authors.lastname: Guerler
authors.forename: Connie
authors.initials: C
authors.lastname: Wang
authors.forename: Ernst-Walter
authors.initials: EW
authors.lastname: Knapp
mesh_terms: D030562:Databases, Protein; D008958:Models, Molecular; D011487:Protein Conformation; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D012399:Rotation
chemical_list: D011506:Proteins