Frag’r’Us: knowledge-based sampling of protein backbone conformations for de novo structure-based protein design

Abstract Motivation The remodeling of short fragment(s) of the protein backbone to accommodate new function(s), fine-tune binding specificities or change/create novel protein interactions is a common task in structure-based computational design. Alternative backbone conformations can be generated de novo or by redeploying existing fragments extracted from protein structures i.e. knowledge-based. We present Frag’r’Us, a web server designed to sample alternative protein backbone conformations in loop regions. The method relies on a database of super secondary structural motifs called s motifs. Thus, sampling of conformations reflects structurally feasible fragments compiled from existing protein structures. Availability and implementation Frag’r’Us has been implemented as web application and is available at http://www.bioinsilico.org/FRAGRUS . Contact narcis.fernandez@gmail.com or baldo.oliva@upf.edu Supplementary information Supplementary data are available at Bioinformatics online.