Protein Structure Hierarchy

The complexity of protein structures requires a description of their structural components. This chapter describes the elements of protein secondary structure — regular local structural patterns — such as helices, sheets, turns, and loops. Helices and sheets tend to fall into specific regions in the {ϕ, ψ} space of the Ramachandran plot (see Figures 28 and 29). The corresponding width and shape of each region reflects the spread of that motif as found in proteins.