The use of Sayre's equation with solvent flattening and histogram matching for phase extension and refinement of protein structures

摘要: A new method for phase refinement and extension, which combines Sayre's equation with solvent flattening histogram matching, has been developed. Equations express electron-density constraints are solved using discrete Fourier transforms to give a approximation the electron density. The formulation of equations is in real space, allows any set be entered directly into calculation. An application known structure 2Zn insulin refined 3 MIR phases from mean error 46 39° extended 2 resolution overall 57°. Analysis errors shows that, strong reflexions, determines half phases.