FOLD: Integrated analysis and display of protein secondary structure

Abstract

FOLD, a computer program for the definition and analysis of protein secondary structure, is described. Algorithms implemented in the software are reviewed. These include methods for the identification of simple features such as hydrogen bonds, α helices, β strands, β bulges, and β and Ψ turns. Techniques are also described for the definition and analysis of higher-order structures, such as β hairpins, β sheets and their topology, and β barrels. In addition to considerable textual output the program supports visualization of protein secondary structure in either an atom-based display style or one reproducing the characteristics of a so-called ribbon drawing.