ScrewFit: combining localization and description of protein secondary structure

Abstract

A new application of theScrewFitalgorithm [Kneller & Calligari (2006),Acta Cryst.D62, 302–311] is presented which adds the detection of protein secondary-structure elements to their detailed geometrical description in terms of a curve with intrinsic torsion. The extension is based on confidence and persistence criteria for theScrewFitparameters which are established by analyzing the structural fluctuations of standard motifs in the SCOP fold classes. The agreement with the widely usedDSSPmethod is comparable with the general consensus among other methods in the literature. This combination of secondary-structure detection and analysis is illustrated for the enzyme adenylate kinase.