An evolutionary computational approach to the phase problem in macromolecular X-ray crystallography.

The ab initio computation of the molecular envelopes of two proteins exclusively from their corresponding diffraction amplitudes demonstrates that an efficient and inherently parallel evolutionary search algorithm can assist in the direct phasing of macromolecules for which almost no a priori structural information is available. The applicability of this evolutionary computational approach is general and should not be limited to the examples described nor to extremes of data resolution, symmetry or structural size.