Optimal data-driven parameterization of coiled coils

alpha-Helical coiled coils (CCs) represent an important, highly regular protein folding motif. To date, many thousands of CC structures have been determined experimentally. Their geometry is usually modelled by theoretical equations introduced by F. Crick that involve a predefined set of parameters. Here we have addressed the problem of efficient CC parameterization from scratch by performing a statistical evaluation of all available CC structures. The procedure is based on the principal component analysis and yields a minimal set of independent parameters that provide for the reconstruction of the complete CC structure at a required precision. The approach is successfully validated on a set of canonical parallel CC dimers. Its applications include all cases where an efficient sampling of the CC geometry is important, such as for solving the phase problem in crystallography.