Refining Protein Envelope with a Transition Region for Enhanced Direct Phasing in Protein Crystallography

Direct method has been tested on solving protein crystal structures directly from the diffraction data. Since direct method starts from random density(or phase), a good strategy to iteratively improve the reconstructed protein envelope is crucial. A transition region was introduced to refine the reconstructed envelope. The resulted envelope enhanced direct phasing with increased phasing speed and improved success rate. The strategy is helpful when phasing protein crystals with irregular protein envelop and less solvent content.